The night sky for December 2017

4 joulu 2017 · The night sky this month

00:20:54

Northern Hemisphere

Ian Morison tells us what we can see in the Northern Hemisphere night sky during December 2017.

The PlanetsJupiter - Jupiter is now a pre-dawn object rising some 2 hours before the Sun at the beginning of the month with its 31 arc second disk, shining at a magnitude of -1.7, to be seen under clear skies. As the month progresses, its apparent diameter increases to 33 arc seconds and it brightens to magnitude -1.8. The low elevation will hinder our view, but the equatorial bands and up to four of its Gallilean moons should be visible.

Saturn - Saturn will not be visible this month as it leaves the evening sky on its way to superior conjunction (passing behind the Sun) on December 21st before it reappears in the pre-dawn sky next year.

Mercury - Mercury, just visible in the evening sky at the end of November, will not be seen for three weeks as it passes between the Earth and the Sun on December 13th (inferior conjunction). From the 20th or so it brightens rapidly in the pre-dawn sky to reach a magnitude of -0.3 by month's end when some 23 degrees away from the Sun. As the ecliptic makes quite a steep angle to the horizon, it will then have a reasonable elevation so making the end of the month an excellent time to observe Mercury. It will then have a magnitude of -0.3 and a disk 6.9 arc seconds across.

Mars - As December begins, Mars lies in Virgo just 3 degrees up to the left of Spica, Alpha Virginis. Now a morning object at the start of its new apparition, it rises four hours or so earlier than the Sun. During the month, Mars has a magnitude increasing from 1.7 to 1.5 and an angular size of just 4.2 (increasing to 4.8) arc seconds so no details will be seen on its salmon-pink surface. Mars crosses from Virgo into Libra on the 21st, moving eastwards to closely approach Jupiter on New Year's Eve before a very close conjunction with it on the 7th of January.

Venus - Venus, was seen in a close conjunction with Jupiter on the 13th November. Moving back towards the Sun, it rises just 45 minutes before the Sun at the start of December and is lost in the Sun's glare around the 12th of the month on its way towards superior conjunction (on the far side of the Sun) on January 9th. In its final week of visibility, it will have a magnitude of -3.9 and disk 9.9 arc seconds across.

HighlightsM31 and M33. Around the 18th of December (with no Moon in the sky): find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum.

December 2nd before dawn: Mars and Jupiter and a last chance to observe Venus for a while. If clear before dawn on the 2nd, there is a last chance for a while of spotting Venus as it sinks down to the Sun with, first, Jupiter and then Mars higher above in the southeastern sky. To spot Venus, a very low horizon will be needed and perhaps binoculars - but please to not use them after the Sun has risen.

December 14th before dawn: Mars, Jupiter and a thin crescent Moon. If clear before dawn on the 14th, there will be a nice grouping of a very thin waning crescent Moon with Mars, to its upper right and Jupiter below.

December 14th and 15th after midnight: the Geminid Meteor Shower. The early mornings of December 14th and 15th will give us the chance, if clear, of observing the peak of the Geminid meteor shower. Pleasingly, this is a great year to observe them as the thin waning crescent moon will not affect our view. The Geminids can often produce near-fireballs and so the shower is well worth observing if it is clear. An observing location well away from towns or cities will pay dividends. The relatively slow moving meteors arise from debris released from the asteroid 3200 Phaethon. This is unusual, as most meteor showers come from comets. The radiant - where the meteors appear to come from - is close to the bright star Castor in the constellation Gemini as shown on the chart. If it is clear it will be cold - so wrap up well, wear a woolly hat and have some hot drinks with you.

December 22nd/23rd - late evenings: the Ursid Meteor Shower. The late evenings of the 22nd and 23rd of December are when the Ursid meteor shower will be at its best - though the peak rate of ~10-15 meteors per hour is not that great. Pleasingly, the Moon soon after new, will not affect our view during much of the night. The radiant lies close to the star Kochab in Ursa Minor (hence their name), so look northwards at a high elevation. Occasionally, there can be a far higher rate so it is worth having a look should it be clear.

December 30/31st ~1 am: The Moon occults Aldebaran. Just after 1 am on the morning of the 31st of December, the near full Moon will occult the red giant star Aldebaran that lies between us and the Hyades cluster. It will disappear behind the dark limb of the Moon just after 1 am (but, due to parallax, the time is dependent on your location in the UK) and reappear just before 2 am.

December 31st - before dawn: three planets in the Southeast. Before dawn on the 31st one will, if clear, be able to spot Jupiter and Mars close together in the pre-dawn sky with elusive Mercury above the horizon down to their lower left. A low horizon towards the Southeast will be needed to pick up Mercury and perhaps binoculars - but please do not use them after the Sun has risen.

December 9th and 26th: The Alpine Valley. Two good evenings to observe the Alpine Valley.

Claire Bretherton from the Carter Observatory in New Zealand speaks about the Southern Hemisphere night sky during December 2017.

Kia Ora and welcome to the December Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.

We're really noticing our days getting warmer now and our evenings getting brighter as we head towards the southern hemisphere summer solstice on the 22nd of December. The eastern evening sky is dominated by our summer constellations of Taurus and Orion, with his two dogs Canis Major and Canis Minor.

The summer Milky Way stretches through these constellations and along our southern horizon. Whilst not as bright as our winter Milky Way, we can still pick out the mottled glow of bright and dark regions when observed from a dark location. The bright regions are the combined light of the many distant stars that form our galaxy, whilst the dark patches are clouds of interstellar gas and dust that block the light from more distant stars. Throughout this region there are many star clusters and nebulae that can be observed with binoculars and small telescopes, and some that can even be seen with the naked eye.

Orion - We'll start our tour of the southern skies in Orion, sitting high in the east after dark, and easy to find by the three bright stars that form his belt. Here in Aotearoa we call these Tautoru, meaning line of three. As he lies along the celestial equator, Orion can be seen (at least partially) throughout the world. Above Orion's belt is a line of faint stars which form Orion's sword, but in New Zealand we see him upside down, so instead his belt and sword become a pot or saucepan.

In Greek mythology Orion is a hunter, and the arch enemy of Scorpius, our winter constellation. The two continually chase each other around the sky. Just as one rises in the east, the other sets below the western horizon.

At the top left of the constellation is the bright blue-white supergiant Rigel or Puanga. Whilst Rigel has been given the Beta designation, it is, in fact, normally the brightest star in the constellation and the seventh brightest in the night sky. Its colour tells us that it is extremely hot, with over twice the temperature and many tens of thousands of times the luminosity of the Sun. With an estimated age of just 8 million years, compared to 4.5 billion years for the Sun, Rigel is a young star, but has already used up all the hydrogen in its core and has swollen out to between 79 and 115 times the Sun's radius. Hot, massive, blue stars like Rigel don't live very long, they live fast and die young, using their fuel quickly before meeting a violent death. Over the next few million years Rigel will expand further and cool to become a red supergiant before ending its life in a massive explosion called a supernova.

Betelguese

At the bottom right of Orion is Betelguese, a star that has already reached the red supergiant phase, bloating out and cooling down to give it its wonderful red hue.

Betelgeuse is designated Alpha Orionis, but is currently the second brightest star in the constellation. Estimates of its mass range from around 8 to 20 times that of the Sun, and if it were placed at the centre of the Solar System its surface would reach out almost as far as the orbit of Jupiter.

One day soon Betelgeuse is also going to end its life in a supernova. Of course, soon to astronomers could be a million years, but if it does go bang within our lifetimes it is sure to be a spectacular sight, perhaps becoming so bright you could see it in the daytime. At a distance of over 600 light years, it is possible that this explosion has already happened and we are just waiting for the light to reach us.

But, as well as stars at the end of their lives, Orion also contains stars whose lives are just beginning. If you look carefully you may see the middle star of Orion's sword has a fuzzy appearance. This is the great nebula in Orion, or M42. The Orion Nebula is a stellar nursery, a huge cloud of gas and dust in which new stars are being born. At around 1,344 light years away, M42 is the closest massive star formation region to the Earth, with around 700 stars in various stages of the star formation process. In the heart of the Orion nebula is a small group of bright stars known as the Trapezium Cluster. The ultraviolet radiation from these stars is lighting up the surrounding gas.

Whilst easily spotted with the naked eye, through binoculars or a small telescope the nebula is a wonderful sight. Take your time and you should be able to clearly see some of the nebulosity of M42 and the bright star cluster that lights it up.

Another nebula in Orion that is well worth a look is the reflection nebula M78, easily found as a hazy patch in a small telescope. With a larger telescope the famous Horsehead nebula, silhouetted against the emission nebula IC434, is a lovely sight just to the south of the star Alnitak, the easternmost star in Orion's belt. Its proximity to bright Alnitak makes viewing the horsehead nebula more challenging, but long exposure photographs will reveal much more detail.

Aldebaran - Following Orion's belt to the left we come to an upturned V shape of stars marking the head of Taurus the bull. At the bottom of this V is the bright orange star Aldebaran, at around 65ly away, representing the eye of the bull. The other stars in the V are part of the more distant Hyades cluster. At 153 ly away, the Hyades is the closest, and one of the best studied, open clusters to Earth. It is estimated to be around 625 million years old. Over time the cluster will continue to spread out and disperse into space, with some of the largest and brightest members already coming towards the ends of their lives.

Crab Nebula - Near to the fainter of the two horns of Taurus, and just about visible in binoculars under excellent conditions, is the Crab Nebula. First discovered by English astronomer John Bevis in 1731, the Crab Nebula is a supernova remnant now believed to be associated with Supernova SN1054, observed and recorded by Chinese astronomers in 1054 AD.

Pleiades - Continuing further around the sky you come to another famous open cluster, the Pleiades, or M45, at a distance of 444ly away. This group of stars is even younger than the Hyades, and is dominated by a number of hot, massive, blue stars only around 100 million years old. The Pleiades has many different names in many different cultures, but here in New Zealand is known as Matariki, meaning little eyes, or eyes of God. The rising of this group of stars for the first time before the Sun, around June, each year marks the coming of the Māori New Year.

Sirius - Following Orion's belt to the right you come to Sirius, or Takurua, the brightest star in our nighttime sky, and in the constellation of Canis Major, Orion's large hunting dog. Canis Minor, the small dog, is a little below, close to the eastern horizon. It contains just two bright stars, and looks like a single line when traced on the sky. Here at Space Place we like to call it the hotdog constellation, as that's the only dog we know of with no head, no legs and no tail. The brighter of the two stars, Procyon, is one of the Sun's nearest stellar neighbours at just 11.46 light years away. Whilst it appears as a single star, the eighth brightest in the night sky, it is actually a binary star system, consisting of a white main-sequence star and a faint white dwarf companion.

Crux - From Orion and his hunting dogs you can follow the band of the Milky Way around the sky, through the False and Diamond Crosses to Crux, the Southern Cross, low in the south. Scanning a pair of binoculars along the Milky Way should pick out glowing gas clouds and numerous star clusters whilst revealing much more detail than the eye can see.

Planets - Both Mercury and Saturn quickly disappear from our dusk skies this month as they move closer to the Sun, leaving our evenings bereft of bright planets. Mars is the first to rise, around 3:30 am at the start of the month, with Jupiter joining it around 40 minutes later. By the end of December Mecury will also reappear in the morning, rising rapidly up the dawn sky to sit just below orange Antares.

We also have a number of meteor showers happening this month. The Phoenicids reach their peak on 6th December and are thought to be associated with the comet D/1819 W1 (Blanpain). With the radiant in the constellation of Phoenix, not far from Achernar, this shower is well placed for southern hemisphere observers throughout the hours of darkness. The Pheonicids were first discovered during an outburst in 1956, where approximately 100 meteors an hour were seen from locations across the southern hemisphere. However, activity is very uncertain, and rates since have been much much lower than this. The minor Puppid-Velids meteor shower also reaches its peak at around the same time with a zenithal hourly rate of around 10, however , the radiant will only rise around 14 degrees above out horizon, so we may only get around 3 an hour.

Just a few days later, peaking on the 15th of the month, are the Geminids. The Geminids are one of the best meteor showers of the year, but we are not well placed for viewing in New Zealand, with the radiant in the constellation of Gemini and well north of the equator. The constellation is at its highest around 3 am, but still appears low in our northern sky. Due to this low height we only see around half of the meteors visible to those in the northern hemisphere.

Wishing you clear skies and a Merry Christmas from the team here at Space Place at Carter Observatory.

Kuuntele Kuuntele uudestaan Jatka Soittaa...
Tilaajat Lopeta tilaaminen
Jaa

Episodit

The night sky for December 2017
4 joulu 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the Northern Hemisphere night sky during December 2017.
The PlanetsJupiter - Jupiter is now a pre-dawn object rising some 2 hours before the Sun at the beginning of the month with its 31 arc second disk, shining at a magnitude of -1.7, to be seen under clear skies. As the month progresses, its apparent diameter increases to 33 arc seconds and it brightens to magnitude -1.8. The low elevation will hinder our view, but the equatorial bands and up to four of its Gallilean moons should be visible.

Saturn - Saturn will not be visible this month as it leaves the evening sky on its way to superior conjunction (passing behind the Sun) on December 21st before it reappears in the pre-dawn sky next year.

Mercury - Mercury, just visible in the evening sky at the end of November, will not be seen for three weeks as it passes between the Earth and the Sun on December 13th (inferior conjunction). From the 20th or so it brightens rapidly in the pre-dawn sky to reach a magnitude of -0.3 by month's end when some 23 degrees away from the Sun. As the ecliptic makes quite a steep angle to the horizon, it will then have a reasonable elevation so making the end of the month an excellent time to observe Mercury. It will then have a magnitude of -0.3 and a disk 6.9 arc seconds across.

Mars - As December begins, Mars lies in Virgo just 3 degrees up to the left of Spica, Alpha Virginis. Now a morning object at the start of its new apparition, it rises four hours or so earlier than the Sun. During the month, Mars has a magnitude increasing from 1.7 to 1.5 and an angular size of just 4.2 (increasing to 4.8) arc seconds so no details will be seen on its salmon-pink surface. Mars crosses from Virgo into Libra on the 21st, moving eastwards to closely approach Jupiter on New Year's Eve before a very close conjunction with it on the 7th of January.

Venus - Venus, was seen in a close conjunction with Jupiter on the 13th November. Moving back towards the Sun, it rises just 45 minutes before the Sun at the start of December and is lost in the Sun's glare around the 12th of the month on its way towards superior conjunction (on the far side of the Sun) on January 9th. In its final week of visibility, it will have a magnitude of -3.9 and disk 9.9 arc seconds across.

HighlightsM31 and M33. Around the 18th of December (with no Moon in the sky): find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum.

December 2nd before dawn: Mars and Jupiter and a last chance to observe Venus for a while. If clear before dawn on the 2nd, there is a last chance for a while of spotting Venus as it sinks down to the Sun with, first, Jupiter and then Mars higher above in the southeastern sky. To spot Venus, a very low horizon will be needed and perhaps binoculars - but please to not use them after the Sun has risen.

December 14th before dawn: Mars, Jupiter and a thin crescent Moon. If clear before dawn on the 14th, there will be a nice grouping of a very thin waning crescent Moon with Mars, to its upper right and Jupiter below.

December 14th and 15th after midnight: the Geminid Meteor Shower. The early mornings of December 14th and 15th will give us the chance, if clear, of observing the peak of the Geminid meteor shower. Pleasingly, this is a great year to observe them as the thin waning crescent moon will not affect our view. The Geminids can often produce near-fireballs and so the shower is well worth observing if it is clear. An observing location well away from towns or cities will pay dividends. The relatively slow moving meteors arise from debris released from the asteroid 3200 Phaethon. This is unusual, as most meteor showers come from comets. The radiant - where the meteors appear to come from - is close to the bright star Castor in the constellation Gemini as shown on the chart. If it is clear it will be cold - so wrap up well, wear a woolly hat and have some hot drinks with you.

December 22nd/23rd - late evenings: the Ursid Meteor Shower. The late evenings of the 22nd and 23rd of December are when the Ursid meteor shower will be at its best - though the peak rate of ~10-15 meteors per hour is not that great. Pleasingly, the Moon soon after new, will not affect our view during much of the night. The radiant lies close to the star Kochab in Ursa Minor (hence their name), so look northwards at a high elevation. Occasionally, there can be a far higher rate so it is worth having a look should it be clear.

December 30/31st ~1 am: The Moon occults Aldebaran. Just after 1 am on the morning of the 31st of December, the near full Moon will occult the red giant star Aldebaran that lies between us and the Hyades cluster. It will disappear behind the dark limb of the Moon just after 1 am (but, due to parallax, the time is dependent on your location in the UK) and reappear just before 2 am.

December 31st - before dawn: three planets in the Southeast. Before dawn on the 31st one will, if clear, be able to spot Jupiter and Mars close together in the pre-dawn sky with elusive Mercury above the horizon down to their lower left. A low horizon towards the Southeast will be needed to pick up Mercury and perhaps binoculars - but please do not use them after the Sun has risen.

December 9th and 26th: The Alpine Valley. Two good evenings to observe the Alpine Valley.

Claire Bretherton from the Carter Observatory in New Zealand speaks about the Southern Hemisphere night sky during December 2017.
Kia Ora and welcome to the December Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
We're really noticing our days getting warmer now and our evenings getting brighter as we head towards the southern hemisphere summer solstice on the 22nd of December. The eastern evening sky is dominated by our summer constellations of Taurus and Orion, with his two dogs Canis Major and Canis Minor.
The summer Milky Way stretches through these constellations and along our southern horizon. Whilst not as bright as our winter Milky Way, we can still pick out the mottled glow of bright and dark regions when observed from a dark location. The bright regions are the combined light of the many distant stars that form our galaxy, whilst the dark patches are clouds of interstellar gas and dust that block the light from more distant stars. Throughout this region there are many star clusters and nebulae that can be observed with binoculars and small telescopes, and some that can even be seen with the naked eye.

Orion - We'll start our tour of the southern skies in Orion, sitting high in the east after dark, and easy to find by the three bright stars that form his belt. Here in Aotearoa we call these Tautoru, meaning line of three. As he lies along the celestial equator, Orion can be seen (at least partially) throughout the world. Above Orion's belt is a line of faint stars which form Orion's sword, but in New Zealand we see him upside down, so instead his belt and sword become a pot or saucepan.

In Greek mythology Orion is a hunter, and the arch enemy of Scorpius, our winter constellation. The two continually chase each other around the sky. Just as one rises in the east, the other sets below the western horizon.
At the top left of the constellation is the bright blue-white supergiant Rigel or Puanga. Whilst Rigel has been given the Beta designation, it is, in fact, normally the brightest star in the constellation and the seventh brightest in the night sky. Its colour tells us that it is extremely hot, with over twice the temperature and many tens of thousands of times the luminosity of the Sun. With an estimated age of just 8 million years, compared to 4.5 billion years for the Sun, Rigel is a young star, but has already used up all the hydrogen in its core and has swollen out to between 79 and 115 times the Sun's radius. Hot, massive, blue stars like Rigel don't live very long, they live fast and die young, using their fuel quickly before meeting a violent death. Over the next few million years Rigel will expand further and cool to become a red supergiant before ending its life in a massive explosion called a supernova.
Betelguese
At the bottom right of Orion is Betelguese, a star that has already reached the red supergiant phase, bloating out and cooling down to give it its wonderful red hue.
Betelgeuse is designated Alpha Orionis, but is currently the second brightest star in the constellation. Estimates of its mass range from around 8 to 20 times that of the Sun, and if it were placed at the centre of the Solar System its surface would reach out almost as far as the orbit of Jupiter.
One day soon Betelgeuse is also going to end its life in a supernova. Of course, soon to astronomers could be a million years, but if it does go bang within our lifetimes it is sure to be a spectacular sight, perhaps becoming so bright you could see it in the daytime. At a distance of over 600 light years, it is possible that this explosion has already happened and we are just waiting for the light to reach us.

But, as well as stars at the end of their lives, Orion also contains stars whose lives are just beginning. If you look carefully you may see the middle star of Orion's sword has a fuzzy appearance. This is the great nebula in Orion, or M42. The Orion Nebula is a stellar nursery, a huge cloud of gas and dust in which new stars are being born. At around 1,344 light years away, M42 is the closest massive star formation region to the Earth, with around 700 stars in various stages of the star formation process. In the heart of the Orion nebula is a small group of bright stars known as the Trapezium Cluster. The ultraviolet radiation from these stars is lighting up the surrounding gas.
Whilst easily spotted with the naked eye, through binoculars or a small telescope the nebula is a wonderful sight. Take your time and you should be able to clearly see some of the nebulosity of M42 and the bright star cluster that lights it up.
Another nebula in Orion that is well worth a look is the reflection nebula M78, easily found as a hazy patch in a small telescope. With a larger telescope the famous Horsehead nebula, silhouetted against the emission nebula IC434, is a lovely sight just to the south of the star Alnitak, the easternmost star in Orion's belt. Its proximity to bright Alnitak makes viewing the horsehead nebula more challenging, but long exposure photographs will reveal much more detail.
Aldebaran - Following Orion's belt to the left we come to an upturned V shape of stars marking the head of Taurus the bull. At the bottom of this V is the bright orange star Aldebaran, at around 65ly away, representing the eye of the bull. The other stars in the V are part of the more distant Hyades cluster. At 153 ly away, the Hyades is the closest, and one of the best studied, open clusters to Earth. It is estimated to be around 625 million years old. Over time the cluster will continue to spread out and disperse into space, with some of the largest and brightest members already coming towards the ends of their lives.

Crab Nebula - Near to the fainter of the two horns of Taurus, and just about visible in binoculars under excellent conditions, is the Crab Nebula. First discovered by English astronomer John Bevis in 1731, the Crab Nebula is a supernova remnant now believed to be associated with Supernova SN1054, observed and recorded by Chinese astronomers in 1054 AD.

Pleiades - Continuing further around the sky you come to another famous open cluster, the Pleiades, or M45, at a distance of 444ly away. This group of stars is even younger than the Hyades, and is dominated by a number of hot, massive, blue stars only around 100 million years old. The Pleiades has many different names in many different cultures, but here in New Zealand is known as Matariki, meaning little eyes, or eyes of God. The rising of this group of stars for the first time before the Sun, around June, each year marks the coming of the Māori New Year.

Sirius - Following Orion's belt to the right you come to Sirius, or Takurua, the brightest star in our nighttime sky, and in the constellation of Canis Major, Orion's large hunting dog. Canis Minor, the small dog, is a little below, close to the eastern horizon. It contains just two bright stars, and looks like a single line when traced on the sky. Here at Space Place we like to call it the hotdog constellation, as that's the only dog we know of with no head, no legs and no tail. The brighter of the two stars, Procyon, is one of the Sun's nearest stellar neighbours at just 11.46 light years away. Whilst it appears as a single star, the eighth brightest in the night sky, it is actually a binary star system, consisting of a white main-sequence star and a faint white dwarf companion.

Crux - From Orion and his hunting dogs you can follow the band of the Milky Way around the sky, through the False and Diamond Crosses to Crux, the Southern Cross, low in the south. Scanning a pair of binoculars along the Milky Way should pick out glowing gas clouds and numerous star clusters whilst revealing much more detail than the eye can see.

Planets - Both Mercury and Saturn quickly disappear from our dusk skies this month as they move closer to the Sun, leaving our evenings bereft of bright planets. Mars is the first to rise, around 3:30 am at the start of the month, with Jupiter joining it around 40 minutes later. By the end of December Mecury will also reappear in the morning, rising rapidly up the dawn sky to sit just below orange Antares.

We also have a number of meteor showers happening this month. The Phoenicids reach their peak on 6th December and are thought to be associated with the comet D/1819 W1 (Blanpain). With the radiant in the constellation of Phoenix, not far from Achernar, this shower is well placed for southern hemisphere observers throughout the hours of darkness. The Pheonicids were first discovered during an outburst in 1956, where approximately 100 meteors an hour were seen from locations across the southern hemisphere. However, activity is very uncertain, and rates since have been much much lower than this. The minor Puppid-Velids meteor shower also reaches its peak at around the same time with a zenithal hourly rate of around 10, however , the radiant will only rise around 14 degrees above out horizon, so we may only get around 3 an hour.

Just a few days later, peaking on the 15th of the month, are the Geminids. The Geminids are one of the best meteor showers of the year, but we are not well placed for viewing in New Zealand, with the radiant in the constellation of Gemini and well north of the equator. The constellation is at its highest around 3 am, but still appears low in our northern sky. Due to this low height we only see around half of the meteors visible to those in the northern hemisphere.

Wishing you clear skies and a Merry Christmas from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for November 2017
7 marras 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the Northern Hemisphere night sky during November 2017.
The PlanetsJupiter
Jupiter passed behind the Sun on October 26th and so will become visible again in the pre-dawn sky after the first week or so November. It will then lie down to the lower left of Venus. However, by the end of November it will rise some two hours before the Sun allowing its 31 arcsecond disk, shining at a magnitude of -1.7, to be observed under clear skies. The low elevation will, of course, hinder our view.
Saturn
Saturn can be seen low in the southwest during twilight this month dropping down towards the horizon a little more each week. Shining at magnitude +0.5, it sets around 2 hours after the Sun on the 1st but little more than one hour by month end. It starts the month moving slowly eastwards in Ophiuchus but reaches the boundary of Sagittarius on the 18th. Last month, Saturn's rings reached their maximum tilt to the line of sight of 27 degrees and it is a real pity that Saturn is so low in the sky. Sadly, this will not improve for quite a few years as Saturn moves slowly through the lowest part of the ecliptic. Towards the end of the month Saturn edges closer to Mercury, but with both so low above the horizon after sunset, will be difficult to spot.
Mercury
Mercury passed between us and the Sun (Superior conjunction) on October 8th and will become visible again after sunset in the latter part of the month. From around the 17th, it might be glimpsed with binoculars low in the southwest 20 minutes after sunset shining at magnitude -0.4. It reaches greatest elongation, 22 degrees east of the Sun on November 23rd but, due to the shallow angle of the ecliptic to the horizon, never lies far above the horizon. In the last few days of the month its magnitude falls to -0.2 and it only lies ~5 degrees above the horizon 30 minutes after sunset.
Mars
Mars, lying in Virgo, has now become a morning object at the start of its new apparition and rises three to four hours earlier than the Sun. During the month, Mars has a magnitude of 1.7 and an angular size of just 3.9 (increasing to 4.2) arc seconds so no details will be seen on its salmon-pink surface. On the 4th, Mars is just three degrees to the upper right of Porrima, Gamma Virginis. This closes to two degrees by the 6th whilst, at the end of the month, it will lie just 3 degrees to the upper left of Spica, Alpha Virginis.
Venus
Venus, now moving back towards the Sun, rises some 90 minutes before dawn at the start of the month but this falls to 45 minutes by month's end. Its magnitude remains at -3.9 during the month as its angular diameter shrinks from 10.4 to 10 arc seconds. However, at the same time, its illuminated phase increases from 96% to 99% - which explains why its magnitude does not change. At the beginning of the month, it lies close to Spica, Alpha Virginis, with Venus some 100 times (5 magnitudes) brighter than Spica. By month's end, binoculars might be needed to spot it low above the eastern horizon. But please do not use them after the Sun has risen.
HIGHLIGHTSNovember - a good month to observe Neptune and Uranus with a small telescope.
Neptune came into opposition - when it is nearest the Earth - on the 2nd of September, so will be well placed to spot this month. Its magnitude is +7.9 so Neptune, with a disk just 3.7 arc seconds across, is easily spotted in binoculars lying in the constellation Aquarius as shown on the charts. It rises to an elevation of ~27 degrees when due south. Given a telescope of 8 inches or greater aperture and a dark transparent night it should even be possible to spot its moon Triton. Uranus reached opposition on October 19th and so is visible all night. It will be highest in the sky in the south around 1 am BST shining at magnitude 5.7 and with a disk 3.7 arc seconds across. It lies in Pisces, one degree and 18 arc minutes up to the right of Omicron Pisces as shown in the accompanying chart. Its turquoise green colour should be seen in a small telescope and it will be easily spotted in binoculars.
Around the 18th of November (with no Moon in the sky): find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum
In the evening, the galaxy M31 in Andromeda is visible in the south. The chart provides two ways of finding it:
Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago! You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right as shown on the chart.
Around new Moon (18th November) - and away from towns and cities - you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies. It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40 or, preferably, 10x50). Follow the two stars back from M31 and continue in the same direction sweeping slowly as you go. It looks like a piece of tissue paper stuck on the sky just a bit brighter than the sky background. Good Hunting.
November early mornings: November Meteors.
In the hours before dawn, November gives us a chance to observe meteors from two showers. The first that it is thought might produce some bright events is the Northern Taurids shower which has a broad peak of around 10 days but normally gives relatively few meteors per hour. The peak is around the 10th of November but then the Moon is close to third quarter so its light will intrude. The meteors arise from comet 2P/Encke. Its tail is especially rich in large particles and, this year, we may pass through a relatively rich band so it is possible that a number of fireballs might be observed!
The better known November shower is the Leonids which peak on the night of the 17th/18th of the month. Happily, the Moon is new so will not hinder our view. As one might expect, the shower's radiant lies within the sickle of Leo and meteors could be spotted from the 15th to the 20th of the month. The Leonids enter the atmosphere at ~71 km/sec and this makes them somewhat challenging to photograph but it is worth trying as one might just capture a bright fireball. Up to 15 meteors an hour could be observed if near the zenith. The Leonids are famous because every 33 years a meteor storm might be observed when the parent comet, 55P/Temple-Tuttle passes close to the Sun. In 1999, 3,000 meteors were observed per hour but we are now halfway between these impressive events hence with a far lower expected rate.
November late night: Comet 2107 O1 (ASASSN).
Throughout November, with binoculars or a small telescope, it should be possible to spot Comet 2107 O1 (ASASSN) as it nears the Pole Star. It was discovered in July by the 'All Sky Automated Survey for Supernovae' and brightened rapidly. Its brightness is now falling but, at magnitude +8 or +9, should be visible near the Pole Star this month.
November 6th - very early morning: The Moon occults Aldebaran and the Hyades Cluster
In the early hours of the 6th November, a near full Moon, passing across the Hyades Cluster (at a distance of 153 light years) will occult the red giant star Aldebaran which lies at a distance of 65 light years in front of the Hyades Cluster.
November 15th - 1 hour before dawn: Mars and a crescent Moon
In the hour or so before dawn, Mars will be seen to the right of a thin Crescent Moon.
November 16th - before dawn: three planets and a crescent Moon
Just before dawn, Mars, a very thin Crescent Moon, Jupiter and Venus will form a lineup along the ecliptic. In the dawn glare, binoculars and a very low eastern horizon will be needed to spot them all but please do not use the binoculars after the Sun has risen.
Claire Bretherton from the Carter Observatory in New Zealand speaks about the Southern Hemisphere night sky during November 2017.
Kia ora and welcome to the November Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
The Planets
Mercury now joins Saturn in our western evening skies. Unfortunately it won't be as easy to spot as its last evening appearance in July-August, as it sets before twilight ends. At the start of the month orange Antares, the brightest star in Scorpius or Te Matau a Maui, will sit between the two planets, but as the stars and Saturn slowly sink closer to the horizon from night to night Mercury climbs higher, sitting level with Antares on the 14th and with Saturn on the 24th, when it also reaches its greatest elongation east.
Constellations
Scorpius/Te Matau a Maui has been dominating our evening skies over the winter months, but is now disappearing from view, ready to reappear in the morning over the coming months. As Scorpius sets in the west, his arch enemy, and our summer constellation, Orion rises towards the east along with Taurus and Canis Major. Antares, which marks the heart of the Scorpion, is also known as Rehua to Maori. It represents one of the four Pou, or pillars, that hold Ranginui, the sky father up in the sky. It sits just above the south western horizon at around 11pm at the beginning of the month. These four pou form the basis of a celestial compass, a map of the night sky that was used to navigate the vast pacific oceans and bring our Polynesian ancestors to Aotearoa/New Zealand.
The other three pou are marked by Matariki (the Pleiades), Tautoru (the belt of Orion) and Takurua (Sirius), which line up along the eastern horizon. Matariki supports one of Rangi's shoulders and marks the rising point of the Sun at the winter solstice. Takurua (Sirius) supports the other shoulder and is the closest bright star to the Sun's rising point at the summer solstice. These two stars represent the extent of the Sun's movement throughout the year. In between, rising directly east, is Tautoru, or the belt of Orion, marking the rising point of the Sun at the time of the equinox.
Stretching from Scorpius around to Orion is Te Waka o Tamareriti, or Tamarereti's canoe, which lines up along the southern horizon in our evening sky. The front of the canoe is marked by the tail of Scorpius, with the sting representing the beautifully carved wood that adorns the prow. The star at the end of the Scorpion's curving tail marks the place where the bow meets the water, whilst Rehua or Antares, marks the crest of a wave as the great waka glides through the waters of the Milky Way.
The Southern cross marks the anchor, Te Punga and the pointers Alpha and Beta Centauri are the anchor line, Te Taura.
Orion marks the stern of the canoe, with the elaborately carved stern post rising all the way up from red Betelgeuse to bluish Rigel. A tall mast rises from the waka all the way to Achernar, high in the south, the brightest star in the southern constellation of Eridanus, the river, which we explored last month. A little below Achernar, the two small fuzzy patches of light that make up the Large and Small Magellanic Clouds mark the waka\92s sails.
Mythology
One story tells of Tamarereti sailing across the sky in his waka with all the stars in kete or baskets. He places the key seasonal and navigational stars in their correct positions in the sky, but he finds he has lots of smaller stars left over. So he capsizes his waka spilling all the smaller stars into the sky forming Te Ika Roa, or the Milky Way. Another story tells of Tamareriti scattering bright pebbles in the dark, lightless sky to help guide his way home. The pebbles became the stars and the wake of his waka formed the Milky Way. The sky we see in the mid-evening in October/November each year is, in fact, the same sky we see just before sunrise around June, the time we celebrate Matariki, or Maori New Year. It is said that the bright star Canopus, or Atutahi (the ariki or high chief of the heavens), pulls up the anchor at the start of the year starting the waka in motion. During the year you can track the progress of Tamarereti's waka as it moves across the sky, one day at a time.
Pegasus
On the opposite side of the sky is the Great Square of Pegasus, the flying horse, leaping over the northern horizon. Last month we talked a little about this wonderful constellation, its brightest star Enif, marking the horse's muzzle, and the beautiful globular cluster, M15. But we can also use Pegasus to help us find some of our nearest galactic neighbours.
Alpheratz and M31
The star at the bottom right of the Great Square of Pegasus is in fact Alpha Andromodae, or Alpheratz, the brightest star in the constellation of Andromeda. Located some 97 light years from Earth it is a spectroscopic binary star whose two components orbit each other in just 100 days. M31 is approaching the Milky Way at 110 km/s and is expected to collide and merge with our own Galaxy in around 4 billion years.
M33
A little higher and towards the east, the Triangulum galaxy or M33 is better placed in our skies. At around 3 million light years from Earth and shining at magnitude 5.7 it is just at the limit of naked eye visibility under excellent conditions, making it one of the most distant objects able to be glimpsed unaided. To find M33, head back from Andromeda towards Mirach and then continue a similar distance to the other side. Whilst spotting it with the naked eye is a real challenge, it is easily observable in a pair of binoculars. With the mass of 10s of billions of Suns, M33 is also approaching us, at around 100,000 kilometres per hour. The most striking feature of the Triangulum Galaxy is a massive region of star formation, known as NGC604, which can be seen with a small telescope. NGC604 is 100 times larger than the Orion Nebula and contains over 200 hot, massive blue stars formed just 3 million years ago. In fact, if it were at the same distance as the Orion Nebula, it would be second brightest to only the Moon in the night time sky.
Leonids Meteor Shower
Look out for the Leonid meteor shower, which peaks around the 17th -18thof the month, when the Earth passes through the trail of dust and debris left behind by the comet Temple-Tuttle. Whilst normally a reliable but fairly quiet meteor shower, observers have noticed that roughly every 33 years the number of meteors observed during the shower shows a marked increase as the Earth passes through the denser parts of the cometary debris trail. The radiant of the shower, from which the meteors appear to originate, is located in the constellation of Leo, which rises only a couple of hours before the Sun in our morning sky. The best time to observe the Leonids is about 2-3 hours before sunrise on the mornings around the peak. Look around 20 degrees away from the radiant point for the best chance of meteor spotting.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
Puuttuva jakso?

Paina tästä ja päivitä feedi.
The night sky for October 2017
5 loka 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during October 2017.
The PlanetsJupiter
Jupiter might just be visible for the first few days of October very low above the west-southwestern horizon after sunset. It passes behind the Sun on October 26th to become visible again in the pre-dawn sky in mid November.
Saturn
Saturn can be seen low in the southwest during twilight this month dropping down towards the horizon a little more each week. Shining at magnitude +0.5, it sets around 3 hours after the Sun on the 1st but nearer 2 hours by month end. It is moving slowly eastwards in Ophiuchus moving closer to the boundary of Sagittarius which it will reach on the 18th of November. This month, Saturn's rings reach their maximum tilt to the line of sight of 27 degrees and it is a real pity that Saturn is so low in the sky. Sadly, this will not improve for quite a few years as Saturn moves slowly through the lowest part of the ecliptic.
Mercury
Mercury passes between us and the Sun (Superior conjunction) on October 8th so will not be visible this month.
Mars
Mars has now become a morning object at the start of its new apparition. Initially lying in Leo, it moves into Virgo on the 12th of the month and is still not easily seen in the pre-dawn sky. During the month, Mars has a magnitude of 1.8 and an angular size of just 3.7 (increasing to 3.9) arc seconds so no details will be seen on its salmon-pink surface. As the month progresses Mars rises higher in the sky before dawn and, as described in the highlights, flirts with Venus at the beginning of the month.
Venus
Venus, now moving back towards the Sun, is visible in the east before dawn this month, rising around 2 hours before sunrise at the start of the month and close to Mars. Its magnitude remains at -3.9 during the month as its angular diameter shrinks from 11.2 to 10.6 arc seconds. However, at the same time, its illuminated phase increases from 91% to 96% - which explains why its magnitude does not change. By month's end, Venus rises just an hour and a half before the Sun and binoculars might be needed to spot it low above the eastern horizon. But please do not use them after the Sun has risen.
HIGHLIGHTSOctober - a good month to observe Neptune and Uranus with a small telescope.
Neptune came into opposition - when it is nearest the Earth - on the 2nd of September, so will be well placed to spot this month. Its magnitude is +7.9 so Neptune, with a disk just 3.7 arc seconds across, is easily spotted in binoculars lying in the constellation Aquarius as shown on the charts. It rises to an elevation of ~27 degrees when due south. Given a telescope of 8 inches or greater aperture and a dark transparent night it should even be possible to spot its moon Triton. Uranus reaches opposition (when it is nearest the Earth) on October 19th and so is visible all night. It will be highest in the sky in the south around 1 am BST shining at magnitude 5.7 and with a disk 3.7 arc seconds across. It lies in Pisces, one degree and 18 arc minutes up to the right of Omicron Pisces as shown in the accompanying chart. Its turquoise green colour should be seen in a small telescope and it will be easily spotted in binoculars.
October 5th - before dawn: Venus and Mars close in the East.
Before dawn on the 5th, Venus and Mars will lie just a quarter of a degree apart in the eastern sky.
October 1st- 14th - evening: Saturn in the Southwest
After dark in the evenings of the first part of the month we will have our last good views of Saturn this apparition. Its rings are at their widest, inclined at 27 degrees to the line of sight.
October 9th - late evening: The Moon and the Hyades Cluster
Late evening on the 9th, rising in the East will be the Hyades Cluster along with a waning Moon.
October 17th - before dawn: Venus and Mars below a thin crescent Moon.
Looking Eastwards before dawn on the 17th, a thin crescent Moon will be seen high above Venus and Mars.
October 24th - after sunset: Saturn below a thin waxing crescent Moon
After sunset on the 24th, Saturn will be seen lying below a thin waxing crescent Moon.
October 11th: Mons Piton and Cassini
Best seen just before Third Quarter, Mons Piton is an isolated lunar mountain located in the eastern part of Mare Imbrium, south-east of the crater Plato and west of the crater Cassini. It has a diameter of 25 km and a height of 2.3 km. Its height was determined by the length of the shadow it casts. Cassini is a 57km crater that has been flooded with lava. The crater floor has then been impacted many times and holds within its borders two significant craters, Cassini A, the larger and Cassini B.
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during October 2017.
Kia ora and welcome to the August Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
The Planets
We're really noticing the lighter mornings and evenings now as the Earth continues its orbit around the Sun and we move closer to our southern hemisphere summer. By the end of October the Sun won't set until around 8pm here in Wellington. As we leave Jupiter behind on its outer orbit it is slowly disappearing from our skies, it still sits low in the west at the beginning of the month, setting as twilight ends, but by mid month will be lost in the sunset.
Saturn
Saturn is now our best bet for evening planet viewing, sitting midway up the western sky after dark. A little below and to the left of the planet is Antares or Rehua, marking the heart of Scorpius, which we call te Matau a Maui, the fish hook of Maui here in New Zealand.Zodiacal Light
October is a good time to look out for the zodiacal light, a triangular glow visible in the west after sunset in a clear, dark sky, tilting up towards Antares. The zodiacal light is caused by sunlight reflecting off dust along the plane of our solar system. This plane is marked by the ecliptic, the apparent path of the Sun across the sky, which runs through the constellations of the zodiac. At this time of year the ecliptic makes a steep angle with the horizon, making the zodiacal light easier to observe.
Neptune and Uranus
Whilst not easily seen with the naked eye, Neptune and Uranus are also in our evenings skies, with Neptune in the constellation of Aquarius and Uranus is in neighbouring Pisces. Uranus reaches opposition on the 20th of the month, when it will be directly opposite the Sun in the sky and overhead at around 1am now that we are observing daylight saving. At magnitude 5.7 it is just on the edge of naked eye visibility, but with binoculars should be easy to spot. A small telescope may reveal it as a disk, with a greenish hue.
Constellations
Just to the north of Pisces is the constellation of Pegasus, the winged horse, which appears to leap across the northern horizon in our late evening sky. Pegasus is easy to spot by the ''Great Square'' of stars that makes up his body.The brightest star in the constellation is the reddish star Epsilon Pegasi, marking the horse's muzzle. This star is commonly known as Enif, deriving from the Arabic word for nose. Epsilon Pegasi is an orange supergiant, around 12 times the mass of the Sun, and with a radius some 185 times larger.
Nearby, to the bottom left of Enif, (and visible in the same binocular field of view) is the globular cluster M15, one of the oldest and best know star clusters in the sky, with an estimated age of around 12 billion years. The cluster is located around 34,000 light years away and measures 175 light years across. M15 is probably the most densely packed globular cluster in our galaxy, with half of its mass concentrated within 10 light years of the centre. It has been suggested that this massive concentration of stars may be caused by a rare type of supermassive Black Hole in the clusters core.M15 also contains the planetary nebula Pease 1, the first to be found within a globular cluster. At magnitude 15.5, this is a faint object, and a telescope with an aperture of at least 300mm would be needed to observe it.
On the opposite side of the sky, the Southern Cross, or Te Punga sits low in the south south west, its long arm pointing up across the sky to Achernar in the south east. Achernar is at the tip of the constellation of Eridanus, the river, and is also known as Alpha Eridani. It is the brightest star in the constellation, and the 9th brightest in the night sky. It is a hot, blue main sequence star around 7 times the mass and over 3000 times the luminosity of the Sun. The traditional name, Achernar, derives from the Arabic phrase ''Al Ahir al Nahr'' meaning the end of the river, although interestingly this name was once given to Theta Eridani, now known as Acamar, which was the brightest star in the constellation visible from Ancient Greece.Achernar spins on its axis extremely quickly, completing one rotation in just over 2 days. This high rotation speed gives the star a flattened shape, with the diameter of its equator over 50% greater than that of its poles. Infrared observations from the Very Large Telescope in Chile have also identified a smaller companion star, with around twice the mass of the Sun. The two are extremely close, with a separation of just over 12 AU, slightly larger than the distance from the Sun to Saturn, and orbit once every 14-15 years, although the highly distorted shape of the primary makes these numbers hard to determine.
Below Achernar, just above the south south east horizon, our second brightest night time star, Canopus, twinkles colourfully. The two make an almost equilateral triangle with the southern celestial pole, the point in the sky directly above the south pole of the Earth, about which the whole sky appears to rotate. Another easy way to find this is to but one hand an Achernar and a second hand on Gamma Crucis at the top of the Southern Cross and clap them together in the middle.
Magellanic Clouds
Between the southern celestial pole and Achernar, and above Canopus, you may be able to spot two small fuzzy patches of light, easily seen with the naked eye on a dark, moonless night. These are the Large and Small Magellanic Clouds, two small irregular dwarf galaxies that neighbour our own. Whilst these galaxies are much smaller than the Milky Way, they still contain billions of stars. To the top-right of the SMC you may spot a faint fuzzy 'star'. This object is not actually associated with the SMC but is a beautiful globular cluster called 47 Tucanae, or NGC 104 located just a tenth of the distance away on the outskirts of our own galaxy. At around magnitude 4.1 it is the second brightest globular cluster in the sky, after Omega Centauri, and can be easily seen with the naked eye. With a binoculars or a small telescope it is a wonderful sight, revealing a densely packed central core, whilst a larger telescope will start to resolve some of its millions of ancient stars.
Orion
At the far end of the long winding river of Eridanus is our summer constellation of Orion, the hunter, with bright, blue Rigel the first star to rise after around 11pm mid-month. Below, and following around and hour and a half later is stunning red Betelgeuse, marking the hunter's shoulder or armpit. We'll be exploring this part of the heavens in much more detail over the next few months as it moves into our evening skies, but this month we turn our attention to the constellation in the morning skies, the best time to see the Orionid meteor shower, the radiant of which lies a little below and to the right of Betelgeuse. The Orionids peak on the 21st-22nd of October when the Earth passes through the trail of dust and debris left behind by Comet Halley. The shower can reach rates of 25 meteors per hour, but from the latitude of New Zealand around 10 per hour is more likely with the radiant below the horizon until the early hours of the morning. The best time to look is in the hours before dawn. Try looking around 20 degrees away from the radiant, so the areas from Taurus around through the top of Orion to Canis Major are probably your best bet. Whilst the meteors may be few and far between they also tend to travel quite long distances on the sky and sometimes leave persistent trails of ionized gas behind them that can last for several seconds. With a new moon on the 20th, just before the peak, leaving us with nice dark skies, you should have a good chance of Orionid spotting this year.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for September 2017
15 syys 2017· The night sky this month
The Night SkyNorthern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during September 2017.
The PlanetsJupiter: Now five months after opposition, Jupiter can still just be seen very low in the southwestern sky after nightfall, lying at an elevation of some 10 degrees 45 minutes after sunset. By month's end it will be at an elevation of just 4 degrees at dusk. With a magnitude of -1.7 and an angular size of ~31 arc seconds it will be at its dimmest and smallest during this year's apparition and is too low for any reasonable telescopic views. At the start of September, Spica, Alpha Virginis, lies some 4 degrees to its lower left. Jupiter, moving eastwards passes 3 degrees to the upper right of Spica on September 11th. Now moving down towards the lower part of the ecliptic, next year it will only have an elevation of 25 degrees when due south whilst for the following two years an elevation of just 18 degrees.

Saturn came into opposition back on June 11th and so will be seen in the southwest as darkness falls and sets late evening. It shines initially at magnitude +0.4 falling to +0.5 during the month and has an angular size of ~16.5 arc seconds. With an angle of 26.8 degrees inclination to the line of sight, the rings are virtually as open as they ever can be. Their maximum tilt, at 27 degrees, will come in October - the first time since 2002. It is sad that Saturn, now lying in the southern part of Ophiuchus between Sagittarius and Scorpius, only reached an elevation of ~17 degrees above the horizon when due south, so hindering our view of this most beautiful planet. If imaging Saturn (or Jupiter), Registax 6 has a tool to align the red, green and blue colour images to largely remove atmospheric dispersion from the image. At somewhat over £100 one can purchase the ZWO atmospheric dispersion corrector which uses two, contra rotating, prisms to carry out an even better correction - and which can also be used for visual observing.

Mercury. has now become a morning object and will form a very tight grouping with Mars and Regulus, in Leo on the morning of the 5th. They will lie about 15 degrees below Venus. Binoculars will be needed to observe them in the bright twilight but please do not use them after the Sun has risen. Rising in elevation during the first part of the month, by the 10th it will have brightened to zero magnitude and lie just half a degree to lower right of Regulus. Mercury reaches greatest elongation, some 18 degrees from the Sun on the 12th - its best morning apparition this year. On the 14th, it lies 11 degrees to the lower left of Venus whilst, before dawn on the 16th, it closes to just 0.3 degrees from Mars. In the final week of September, moving back towards the Sun, it will be lost in the Sun's glare. .

Mars has now become a morning object at the start of its new apparition. Lying in Leo, and still not easily seen in the pre-dawn sky, it forms a tight grouping with Mercury and Regulus on the 5th some 15 degrees to the lower left of Venus. During the month, Mars has a magnitude of 1.8 and an angular size of just 3.6 arc seconds so no details will be seen on its salmon-pink surface. As the month progresses Mars rises higher in the sky before dawn and moves closer to Venus which is now moving back towards the Sun

Venus is visible in the east before dawn this month, rising around 2 hours before sunrise. Its magnitude remains at -3.9 during the month as its angular diameter shrinks from 12.4 to 11.2 arc seconds. However, at the same time, its illuminated phase increases from 84 percent to 91 percent - which explains why its magnitude does not change.

Highlights of the Month
September - Find the globular cluster in Hercules and spot the 'Double-double' in Lyra: There are two very nice objects to spot with binoculars in the south-eastern sky well after dark this month. Two thirds of the way up the right hand side of the 4 stars that make up the 'keystone' in the constellation Hercules is M13, the best globular cluster visible in the northern sky. Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae, often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name!
September - A good month to observe Neptune with a small telescope. Neptune comes into opposition - when it is nearest the Earth - on the 2nd of September, so will be well placed to spot this month. Its magnitude is +7.9 so Neptune, with a disk just 3.7 arc seconds across, is easily spotted in binoculars lying in the constellation Aquarius as shown on the charts. It rises to an elevation of ~27 degrees when due south. Given a telescope of 8 inches or greater aperture and a dark transparent night it should even be possible to spot its moon Triton.
September 5th - before dawn: Mars Mercury and Regulus. Before dawn on the 5th, Mercury and Mars will be seen in a close grouping with Regulus in Leo. A very low eastern horizon will be needed to spot them with the use of Binoculars - but please do not use them after the Sun has risen. [The magnification given by the binoculars reduces the effective brightness of the pre-dawn light.]
September 12th - before dawn: the Moon closes on the Hyades Cluster. Before dawn on the 12th, the Moon will be seen closing onto the Hyades Cluster in Taurus.
September 16th - before dawn: three planets below the Moon. Before dawn on the 16th, a thin crescent Moon will be seen high above Venus, Mars and Mercury. Regulus lies between Venus and Mercury.
September 26th - after sunset: Saturn below the crescent Moon. After sunset on the 26th, Saturn will be seen lying below the Moon.
September: 12th and 28th: the Alpine Valley. These are good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the limb is the Appenine mountain chain that marks the edge of Mare Imbrium. Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image a thin rill runs along its length which is quite a challenge to observe. Over the next two nights following the 28th the dark crater Plato and the young crater Copernicus will come into view. This is a very interesting region of the Moon!
Southern Hemisphere
Claire Bretherton tells us what we can see in the southern hemisphere night sky during September 2017.
Kia ora and welcome to the August Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
The PlanetsSaturn: After what felt like a long, cold, wet winter here in Wellington, September marks the start of spring in the southern hemisphere. As we head towards the equinox on the 23rd of the month we see a rapid change in our daylight hours, with our days getting longer and our nights shorter. Equinox means "equal night" because we have the same number of hours of daylight and the same number of hours of darkness at this time of year. By the end of September the Sun won't be setting until nearly half past 7.The mission has revealed the complexity of Saturn's ring system, identified numerous new moons, and provided some of the most stunning images of the solar system that we have ever seen. It has found liquid oceans and a thick atmosphere on Titan, with conditions that may be similar to early Earth, and exploration of the icy moon Enceladus has revealed a hot spot at the southern pole, icy jets spewing out from the surface and a vast ocean below the ice.

Neptune: Whilst there are only two evening planets you can see with your own eyes, Neptune is also in our evening skies, with Uranus joining it before 10pm. Both can be picked out with binoculars, and you may even notice a greenish colour to Uranus, but Neptune will be indistinguishable from a faint star.Now is the best time to look for the eighth planet though, as it reaches opposition on the fifth of the month, when it will be directly opposite the Sun in the sky and at its highest in the north at midnight. At around this time the planet will also be at its closest and brightest, shining at magnitude 7.8, and is sat less than a degree just below and to the right of the 3.8 magnitude star lambda aquarii, but you'll still probably need a detailed finder chart to spot it. Unfortunately, the full moon passes close to Neptune just after opposition, so it may be easier to find a week or two later.

Stars
The bright stars Vega and Canopus mark north-south around dusk this month, guiding our eye to the bright band of the Milky Way passing high overhead. Along with the nearby bright stars of Deneb, in Cygnus the swan, and Altair, in Aquila the eagle, Vega forms part of the "winter triangle" as seen here in the southern hemisphere.
To the south-east of Capricornus is the faint constellation of Piscis Austrinus, the southern fish, with its only bright star, Fomalhaut, marking the mouth of the fish. Fomalhaut is the 18th brightest star in the night sky, and the only, lonely bright star in its vicinity.Follow up observations, however, failed to confirm the planet and left many doubting its existence. It took until 2012 before Fomalhaut b was independently detected and confirmed. Its controversial past has earned it the nickname "the zombie planet", a planet resurrected from the dead.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for August 2017
11 elo 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during August 2017.

The PlanetsJupiter Now four months after opposition, Jupiter can still be seen low in the southwestern sky after nightfall. It sets at about 1 am BST as July begin. As the month progresses its brightness falls from -1.9 to -1.7 magnitudes as its angular size falls from 34 to 32 arc seconds. It lies in Virgo, initially some 8 degrees to the west of Spica, reducing to 4 degrees as the month progresses and will pass Spica on September 11th on its journey towards the lower parts of the ecliptic. Next year it will only reach an elevation of some 25 degrees when due south and, in the following two years, just 18 degrees before it moves back towards the more northerly parts of the ecliptic. Even so, with a small telescope one should easily be able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Gallilean moons as they weave their way around it.

Saturn came into opposition on June 11th and so will be at its highest elevation due south as darkness falls. It shines initially at magnitude +0.3 falling to +0.4 during the month and has an angular size of ~17 arc seconds. With an angle of 26.8 degrees inclination to the line of sight, the rings are virtually as open as they ever can be. Their maximum tilt, at 27 degrees, will come in October - the first time since 2002. Saturn ceases its westwards, retrograde, motion on August 25th. It is sad that Saturn, now lying in the southern part of Ophiuchus between Sagittarius and Scorpius, only reaches an elevation of ~17 degrees above the horizon when due south so hindering our view of this most beautiful planet. If imaging Saturn (or Jupiter), Registax 6 has a tool to align the red, green and blue colour images to largely remove atmospheric dispersion from the image. At somewhat over £100 one can purchase the ZWO atmospheric dispersion corrector which uses two, contra rotating, prisms to carry out an even better correction - and which can also be used for visual observing.

Mercury Given a very low western horizon, Mercury, showing an 8 arc second disk and shining at magnitude +0.4 might just be seen after sunset at the beginning of August. Binoculars may well be needed but please do not use them until after the Sun has set. It passes between the Earth and the Sun (inferior conjunction) on August 26th.

Mars passed behind the Sun in July, but will be hidden in the Sun's glare all month so cannot be observed.

Venus is visible in the east before dawn this month, rising around 3 hours before sunrise. Its magnitude dims slightly during the month from -4 to -3.9 as its angular diameter shrinks from 14.5 to 12.5 arc seconds. However, at the same time, its illuminated phase increases from 74 to 83% which explains why the magnitude does not drop too much. Its elevation before sunrise is greatest on August 2nd when Venus lies close to the open cluster M35 in Gemini.

Highlights of the Month
August - Find the globular cluster in Hercules and spot the 'Double-double' in Lyra. Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae, often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name!
August - A good month to observe Neptune with a small telescope. Neptune comes into opposition - when it is nearest the Earth - on the 2nd of September, so will be well placed both this month and next. Its magnitude is +7.9 so Neptune, with a disk just 3.7 arc seconds across, is easily spotted in binoculars lying in the constellation Aquarius as shown on the chart. It rises to an elevation of ~27 degrees when due south. Given a telescope of 8 inches or greater aperture and a dark transparent night it should even be possible to spot its moon Triton. (This is my objective around the end of the month!)
The Moon and Saturn - Late evening on the 2nd of August, the waxing Moon will be seen to the upper right of Saturn. Antares lies down to its lower right.
The mornings of August 12th and 13th: midnight to dawn - look out for the Perseid meteor shower. If clear, these mornings should give us a chance of observing the Perseid meteor shower - produced by debris from the comet Swift-Tuttle. The early morning of the 12th August will give us the best chance, if clear, of viewing the shower, but the peak is quite broad and so it is well worth observing on the nights before and after. Most meteors are seen looking about 50 degrees from the 'radiant' which lies between Perseus and Cassiopeia. This year a gibbous Moon rises before midnight so will be low in the sky for some time the early hours of the 12th so it will be best to observe them as soon as it is really dark. Moonlight will hinder our view, but it should still be possible to spot many meteors. NB: As we need to view a very wide area of sky, normal binoculars would be of no use, but the Vixen SG 2.1 x 42 that I have just reviewed in the Astronomy Digest, could be useful as they will darken skylight from the Moon somewhat and enable fainter meteors to be seen - albeit over a smaller field of view.
16th August 07:40 - 08:40 BST: A daylight Occultation of Aldebaran - In the early morning of the 16th, Aldebaran will be occulted by the Moon - visible with a telescope (but keep it well away from the Sun). The times are for London and will vary somewhat across the country. In a line from Leverburgh on the Isle of Harris across to Wick, a grazing occultation will be seen at 8:01 BST.
19th August - before dawn: Venus and a thin crescent Moon - Before dawn on the 19th, if clear, Venus will be seen just 2 degrees above a very thin waning crescent Moon.
25th August - after sunset: Jupiter below a thin crescent Moon - After sunset on the 25th, if clear, Venus will be seen below a thin waxing crescent Moon.
August 14th and 30th: The Straight Wall - The Straight Wall, or Rupes Recta, is best observed either 1 or 2 days after First Quarter (30th August: evening best) or a day or so before Third Quarter (evening of the 14th August best). To honest, it is not really a wall but a gentle scarp - as Sir Patrick has said "neither is it a wall nor is it straight"!
Claire Bretherton tells us what we can see in the southern hemisphere night sky during August 2017.

Kia ora and welcome to the August Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
The PlanetsMercury finishes its best evening appearance of the year this month. At the beginning of August it sits low in the west after dark, just above Regulus, the brightest star in Leo, setting around 7:45. By mid month it will disappear from view, lost in the evening twilight as it heads back towards the Sun in our skies. Jupiter is a little further north, midway up our northwestern skies. It is slowly moving below and towards the right of Spica over the course of the month. Both are quickly dropping down our evening skies, with Jupiter setting at around 11pm at the beginning of August, but by around 9:30 at the end.

Saturn - Further around still, Saturn is high in the northeast after dark, with Antares above and to the left, and remains in our sky for most of the night. A waxing gibbous moon passes close to Saturn on the 3rd and 31st of the month, whilst on the evening of the 25th, a thin 3 day old crescent Moon will sit just below Jupiter.

The Moon - On the 22nd of August the Moon will pass directly between the Earth and the Sun, causing a total Solar eclipse. The eclipse path will run across the United States, but unfortunately no part of it will be visible from New Zealand. The next total Solar eclipse visible from our shores won't be until July 2028.

Constellations
Last month we looked at some of the amazing objects in Scorpius and Sagittarius, towards the centre of the Milky Way. This month we'll move along a little from our Galaxy's bright centre to where it passes overhead through Centaurus, Crux, the Southern Cross, and the constellations of Carina, Vela and Puppis that make up the great ship Argo Navis.
Crux - Crux, the Southern Cross lies on its side after sunset in the south western sky, with the Diamond Cross and false cross below. Above Crux are Alpha and Beta Centauri, the brightest stars in the constellation of Centaurus. Known as the pointers, they guide our eye to Gamma Crucis, the star at the top of Crux, and help us identify the true Southern Cross.
Omega Centauri - To the right of the pointers, and just outside the main band of the Milky Way is the spectacular globular cluster Omega Centauri. This is by far the largest and brightest globular cluster in the Milky Way appearing as a fuzzy star to the naked eye. With binoculars it is an even more stunning sight, spanning almost a full degree of the sky, twice that of the full moon, whilst a small telescope will show a shimmering ball of stars, with many individual stars visible towards the outskirts.
The Jewel Box - Close to Beta Crucis, in the Southern Cross, is a different type of star cluster. NGC 4755, also known the "Jewel Box", is an open cluster about 6,500 light years away. It is rich and bright with the stars showing an array of different colours, highlighted by an orange-red supergiant. At magnitude 4.2, the Jewel Box can easily be seen with the naked eye. It is dominated by an A-shaped asterism of bright stars, which is observable with binoculars, whilst even a small telescope will reveal a stunning sight. The name comes from Sir John Herschel's vivid description of the cluster as a "casket of variously coloured precious stones".

The colours of these stars tell us how hot they are. The red stars are the coolest, with temperatures around 3000K, yellow stars like our Sun are closer to 6000K, whilst the hottest, bluest stars reach temperatures of 30,000 Kelvin or more. In order to get this hot these stars have to use a huge amount of fuel very quickly, so they don't live very long - they live fast and die young. The most massive live for just a few million years. The fact that NGC4755 still contains a number of these hot blue stars tells us that it is relatively young, in fact it is one of the youngest star clusters known, with an estimated age of just 14 million years.
Coal Sack - Just to the left is a dark patch known as the Coal Sack nebula. This is a huge cloud of interstellar dust and gas some 700 light years away. It is so thick and dense that it obscures the light from more distant stars, appearing as a darkened area against the bright backdrop of the Milky Way. Aboriginal astronomers have observed the Coalsack for at least 40,000 years, whilst to Māori here in New Zealand it is known as te Patiki or the flounder.
Carinae Cluster - Below the Coalsack, at the tip of the Diamond Cross asterism in Carina is the Theta Carinae cluster, or IC 2602, an open cluster containing around 60 individual stars. At magnitude 1.9 it is the third brightest open cluster in the sky and is often known as the Southern Pleiades, although it is still much fainter than its northern counterpart. The cluster spans around 50 arcminutes, over 1.5 full moon diameters, so it is best viewed with binoculars or a low powered telescope giving a wide field of view.
Carinae Nebula - Around 4 degrees to the right of Theta Carinae is the famous NGC 3372, the Eta Carina nebula, a huge cloud of glowing gas estimated to be around 7500 ly away. At 4 times the size of the Orion Nebula, it is one of the largest nebulae of its type in our skies. With the naked eye you'll be able to pick out the brightest central areas, but with binoculars you should be able to see Eta Carinae itself as a golden star within the nebula. Eta Carinae is actually a system of at least two stars, which combined are around 5 million times more luminous than our Sun. The largest has around 90 times the Sun's mass and is so bright that the radiation pressure it produces is almost too strong for the gravity holding it together, causing a constant stream of material out into space.
Highlights of the Month
Venus - In the morning skies, Venus is now rising around 5am. The Moon will pass nearby on the 19th, sitting just above Venus in the north east at sunrise. The two will move towards the north by midmorning, providing a perfect opportunity to try and spot Venus in the daylight, with Venus sat just to the right of a thin waning crescent Moon.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for July 2017
5 heinä 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during July 2017.
The PlanetsJupiter - Now three months after opposition, Jupiter still dominates the low southwestern sky after nightfall. It sets at about 1 am BST as July begins. As the month progresses its brightness falls from -2.0 to -1.9 magnitudes as its angular size falls from 37 to 34 arc seconds. It lies in Virgo some 10.5 degrees to the west of Spica, now moving eastwards again after its period of retrograde motion. It will pass Spica on September 11th on its journey towards the lower parts of the ecliptic. Next year it will only reach an elevation of some 25 degrees when due south and, in the following two years, just 18 degrees before it moves back towards the more northerly parts of the ecliptic. Even so, with a small telescope one should easily be able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Galilean moons as they weave their way around it. Saturn - Saturn came into opposition on June 11th and so will be at its highest elevation due south at around midnight BST as July begins but by ~10 pm BST at its end. It will be visible throughout most of the short night. It shines initially at magnitude 0.1 falling to +0.2 during the month and has an angular size of ~18 arc seconds. With an angle of 26.7 degrees inclination to the line of sight, the rings are virtually as open as they ever can be. It is sad that Saturn, now lying in the southern part of Ophiuchus between Sagittarius and Scorpius, only reaches an elevation of ~17 degrees above the horizon when due south so hindering our view of this most beautiful planet. If imaging Saturn (or Jupiter), Registax 6 has a tool to align the red, green and blue colour images to largely remove atmospheric dispersion from the image. At somewhat over 100 GBP one can purchase the ZWO atmospheric dispersion corrector which uses two, contra rotating, prisms to carry out an even better correction - and which can also be used for visual observing. Mercury - Mercury reaches greatest elongation east, some 27 degrees from the Sun, on July 30th. It can be seen low in the west-northwest around 30 minutes after sunset. Binoculars may well be needed but please do not use them until after the Sun has set. It fades slightly during the month from -1.0 to +0.4 magnitudes whilst its angular size increases from 5.3 to 7.8 arc seconds. No surface details will, of course, be seen. Mars - Mars is hidden in the Sun's glare all month so cannot be observed. Venus - Venus is visible in the east before dawn this month rising around 2.5 hours before sunrise increasing to 3 hours as the month progresses. It magnitude dims slightly during the month from -4.2 to -4.0 as its angular diameter shrinks from 18.2 to 14.6 arc seconds. However, at the same time, its illuminated phase increases from 63 to 74% which explains why the magnitude does not drop too much. Even though it will be moving back towards the Sun, as the angle of the ecliptic to the horizon increases at this time of the year, it elevation before sunrise will continue to increase until August. Venus passes the Pleiades Cluster on the 5th, the Hyades on the 13/14th and ends the month close to M35 in Gemini.Highlights
June - The best month to observe Saturn - Saturn reached opposition on the 14th of June, so is now due south and highest in the sky in the late evening. It lies in the southern part of Ophiuchus some 16 degrees up and to the left of the orange star Antares in Scorpius. Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good 'seeing' (when the atmosphere is calm) will show Saturn and its beautiful ring system in its full glory.Due to the orientation of Saturn's rotation axis of 27 degrees with respect to the plane of the solar system, the orientation of the rings as seen by us changes as it orbits the Sun and twice each orbit they lie edge on to us and so can hardly be seen. This last happened in 2009 and they are now fully opened out, currently at an angle of 26.5 degrees to the line of sight. From this month the ring's orientation will begin to narrow until March 2025 when they will appear edge-on again.
July - Find the globular cluster in Hercules and spot the "Double-double" in Lyra - There are two very nice objects to spot with binoculars in the eastern sky well after dark this month. Two thirds of the way up the right hand side of the 4 stars that make up the "keystone" in the constellation Hercules is M13, the best globular cluster visible in the northern sky. The 15 minute exposure image on right was taken by the author using a 127 mm APO refractor and SBIG 8.3 megapixel CCD camera. Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name!
Early July - A very good time to spot Noctilucent Clouds! - Noctilucent clouds, also known as polar mesospheric clouds, are most commonly seen in the deep twilight towards the north from our latitude. They are the highest clouds in the atmosphere at heights of around 80 km or 50 miles. Normally too faint to be seen, they are visible when illuminated by sunlight from below the northern horizon whilst the lower parts of the atmosphere are in shadow. They are not fully understood and are increasing in frequency, brightness and extent; some think that this might be due to climate change! So on a clear dark night as light is draining from the north western sky long after sunset take a look towards the north and you might just spot them!
July 7th/8th - midnight: The Moon and SaturnLate evening on the 7th July, the waxing Moon will be seen to the upper right of Saturn.
20th July - before dawn: Venus, Aldebaran and a thin crescent Moon - Before dawn on the 20th, Venus will be seen over to the left of a very thin waning crescent Moon. Aldebaran, lying in front of the Hyades Cluster, will also be seen to the upper right of the Moon.
July 25th - after sunset: The Moon and Mercury - After sunset on the 25th July, given a low western horizon and clear skies, there is a chance of spotting Mercury down to the right of a very thin crescent Moon. Binoculars may well be needed but please do not use them until after the Sun has set.
July 1st and 15th: The Alpine Valley - These are two good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the terminator is the Appenine mountain chain that marks the edge of Mare Imbrium. Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image a thin rill runs along its length which is quite a challenge to observe. Over the next two nights the dark crater Plato and the young crater Copernicus will come into view. This is a very interesting region of the Moon!
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during July 2017.
Kia ora and welcome to the July Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
Jupiter is still high in our evening skies this month, midway up the northwestern sky after sunset. Shining at magnitude -2.1, with its bright golden glow, Jupiter will be the first star-like object you'll see as the sky begins to darken. Just above is bluish Spica, representing the "ear of wheat" held by Virgo. The waxing crescent moon will pass close to Jupiter on both the 1st and 29th of the month.
Lower in the west, Mercury is making an appearance in the evening sky. At the start of the month it sets just an hour after the Sun, but by the end of July, when it reaches its greatest elongation from the Sun, it will remain in our skies until 8pm. On the 25th Mercury will form a close group with Regulus, in Leo, and a thin crescent Moon.
Saturn is high in the northeast and is a great target for a telescope of any size, with its rings still at almost maximum tilt. Look out for Saturn's largest moon Titan looking like a star at around 4 times the ring diameter from the planet. Saturn continues to sit just below Antares in Scorpius, with the claws of the scorpion to the left and his tail curling around to the right. In New Zealand we see this as the fish hook of Māui, Te Matau a Maui.
Below Scorpius is an upside down teapot formed from the brightest stars in the constellation of Sagittarius. The bright centre of the Milky Way runs through Scorpius and sagitarrius, so there are many stunning objects to explore in this part of the sky.
Lying along the tail of the scorpion, close to the orange 3rd magnitude star Zeta Scorpii, is NGC 6231, a bright cluster of stars which looks like a small comet. At magnitude 2.6 this is easily visible to the naked eye. Estimated to be only 3.2 million years old and nearly 6000 light-years away, NGC6231 covers an area of the sky similar in size to the Pleiades, but its stars are much more luminous. If the cluster was placed at the same distance as the Pleiades then some of its stars would be amongst the brightest in the night time sky. With a good pair of binoculars, from a dark sight, NGC 6231 appears in an area of nebulosity and intermingled with open clusters Trumpler 24 and Collinder 316 to form a lovely complex sometimes known as the Scorpius Lizard. Also nearby is NGC 2642. With binoculars its three brightest stars stand out from a faint background glow.
A little above, NGC 6193 is also visible to the naked eye at magnitude 5.2, and nearby NGC 6167 is worth a look in binoculars or a small telescope.
Below, about halfway between the scorpion's sting and the spout of the teapot is M7. This is another open cluster of stars easily visible to the naked eye at magnitude 3.3, and a lovely sight through a good pair of binoculars. It contains about 80 stars brighter than 10th magnitude and covers an area of 1.3 degrees diameter. Current estimates suggest a distance of 980 light years and an age of 220 million years old – still pretty young in astronomical terms. M7 has been known since ancient times and was first recorded by Ptolomy in 130 AD, who described it as a "nebula following the sting of Scorpius", because of this it is also sometimes referred to as the Ptolomy cluster. Nearby and somewhat fainter, the Butterfly cluster, or M6 is also a nice sight in binoculars. The stars will all appear to be at around the same brightness, and the open winged shape that gives the cluster its name should be easy to pick out.
To the left of the teapot's spout, and just about visible to the naked eye, is another lovely Messier object, the Lagoon Nebula, or M8. This is a huge cloud of interstellar gas and dust where new stars are being formed. M8 is a great example of an HII region, where the UV radiation from hot young stars is ionizing the leftover hydrogen gas and causing is to glow. These emission nebulae often appear pink in colour photographs and the Lagoon Nebula is a good target for binoculars or a small telescope.
Another good target is the Trifid nebula, discovered by Charles Messier in 1764, and famed for the three-lobed appearance, which earned it it’s name. It is an interesting object to observe as it combines both an emission and reflection nebula along with an open cluster of stars.
There are also a number of globular clusters in this part of the sky. The brightest is M4, and this is also one of the easiest to find, lying just 1.3 degrees west of Antares. Appearing as a small fuzzy ball in binoculars or small telescopes, a slightly larger telescope will begin to pick out individual stars.
Also in this region, near the top of the teapot, is M22, one of the first globular clusters ever discovered in 1665, and one of the closest at just 10,600 light-years.
From its bright centre the Milky Way stretches overhead through Crux, the Southern Cross, and on to Carina, Vela and Puppis above the southwestern horizon. Together these three constellations make up the great ship Argo Navis, famous in Greek mythology as that used by Jason and the Argonauts in their quest for the Golden Fleece.
Just to the left of the Milky Way is Carina’s brightest star Canopus, or Alpha Carinae, the second brightest in the nighttime sky. Its Maori name is Atu tahi or Au tahi, which means to stand alone, because of its position just outside the main band of our Galaxy. In the other direction , the Milky Way drops down to the eastern horizon and the bright star Altair in the constellation of Aquila, the Eagle, which rises around 9pm at the start of the month.
In the morning skies our last visible planet, brilliant Venus, rises after 4am. Venus is so bright that you can really only mistake it with the headlights of an airplane and provides a useful pointer to help find Matariki/the Pleiades as the cluster rises before dawn. Venus sits just above Matariki at the beginning of the month, but slowly moves down between Matariki and Taurus' brightest star Aldebaran as the month progresses, sitting just below Aldebaran on the morning of the 18th.
Wishing you clear skies from the team her at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for June 2017
10 kesä 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during June 2017.
The PlanetsJupiter - Now two months after opposition, Jupiter still dominates the late evening sky shining in the south to southwest after nightfall. It sets about 3 am BST as June begins and by about 1 am at its end. As the month progresses its brightness falls from -2.3 to -2 .0 magnitudes as its angular size falls from 41 to 37 arc seconds. It lies in Virgo some 11 degrees to the west of Spica, Alpha Virginis, and halts its westwards retrograde motion on the 11th as it begins its initially slow eastwards march back towards Spica. It will pass Spica on September 11th on its journey towards the lower parts of the ecliptic. Next year it will only reach an elevation of some 25 degrees when due south and, in the following two years, just 18 degrees before it moves back towards the more northerly parts of the ecliptic. Even so, with a small telescope one should easily be able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Gallilean moons as they weave their way around it.Saturn - Saturn comes into opposition on June 11th and so, then, will be at its highest elevation due south at around 1 am BST and will be visible throughout the short night. It shines at magnitude 0.1 all month and has an angular size of 18.3 arc seconds. With an angle of 26.5 degrees inclination to the line of sight the rings are virtually as open as they ever can be. It is sad that Saturn, now lying in the southern part of Ophiuchus between Sagittarius and Scorpius, only reaches an elevation of ~17 degrees above the horizon when due south so hindering our view of this most beautiful planet. If imaging Saturn (or Jupiter), Registax 6 has a tool to align the red, green and blue colour images to largely remove atmospheric dispersion from the image. At somewhat over £100 one can purchase the ZWO atmospheric dispersion corrector which uses two, contra rotating, prisms to carry out an even better correction.Mercury - Mercury is lost in the glare of the Sun for most of the month before it makes a modest evening apparition in July. It might just be spotted with binoculars very low in the west after sunset at the very end of the month. But please do not use them until after the Sun has set.Mars - Following a two year long apparition, Mars finally slips into the Sun's glare in the first week of June when its salmon-pink disk might just be picked out in the west-northwest.Venus - Venus is visible in the east before dawn this month reaching its greatest elongation (46 degrees west of the Sun) on the 3rd of June. It magnitude dims slightly during the month from -4.5 to -4.2 as its angular diameter shrinks from ~24 to 18 arc seconds. However, at the same time, its phase increases from 48 to 62 percent which explains why the magnitude does not drop too much. Even though it will be moving back towards the Sun, as the angle of the ecliptic to the horizon increases at this time of the year, it elevation before sunrise will continue to increase until August.Highlights
Early June - still worth viewing Jupiter. .The features seen in the Jovian atmosphere have been changing quite significantly over the last few years - for a while the South Equatorial Belt vanished completely) but has now returned to its normal wide state.

June - The best month to observe Saturn. .The thing that makes Saturn stand out is, of course, its ring system. The two outermost rings, A and B, are separated by a gap called Cassini's Division which should be visible in a telescope of 4 or more inches aperture if seeing conditions are good. Lying within the B ring, but far less bright and difficult to spot, is the C or Crepe Ring. Due to the orientation of Saturn's rotation axis of 27 degrees with respect to the plane of the solar system, the orientation of the rings as seen by us changes as it orbits the Sun and twice each orbit they lie edge on to us and so can hardly be seen. This last happened in 2009 and they are now opening out, currently at an angle of 26.5 degrees to the line of sight. From this month the ring's orientation will begin to narrow until March 2025 when they will appear edge-on again.
June - Find the globular cluster in Hercules and spot the 'Double-double' in Lyra.Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name!
Late June: A very good time to spot Noctilucent Clouds! .Noctilucent clouds, also known as polar mesospheric clouds, are most commonly seen in the deep twilight towards the north from our latitude. They are the highest clouds in the atmosphere at heights of around 80 km or 50 miles. Normally too faint to be seen, they are visible when illuminated by sunlight from below the northern horizon whilst the lower parts of the atmosphere are in shadow. They are not fully understood and are increasing in frequency, brightness and extent; some think that this might be due to climate change! So on a clear dark night as light is draining from the north western sky long after sunset take a look towards the north and you might just spot them!
June 3rd - evening: The Moon and Jupiter.During the evening of the 3rd June, the waxing Moon will lie less than 2 degrees up and to the right of Jupiter.
8th/9th June - around midnight: Observe the Galilean Satellites. .If clear around midnight the 8th/9th, and using a small telescope, one could observe the 4 Gallilean Moons lined up on one side of the giant planet.
Night of June 15 to 16th when fully dark: The Lyrid Meteor Shower.The June Lyrid meteor shower reaches its peak on the night of the 15th/16th with a rate at the zenith of ~8 meteors per hour. This is not many and, as the Moon is close to third quarter it may be hard to spot one. The radiant is very close to the star Vega. Many more meteors were seen from the shower in the late 1960's but the peak hourly rate has dropped off markedly since then. If clear, it may still be worth aiming to see if you can spot one.
21st June - before dawn: Venus and a thin crescent Moon.Before dawn on the 22st, Venus will be seen some 4 degrees above a very thin waning crescent Moon.
Late June - around midnight: Observe Comet 2015 V2 (Johnson) .On the 12 June but, sadly, close to Full Moon, Comet Johnson is at perihelion lying at a distance of 1.64 AU from the Sun. On the 1st of June it will lie over to the left of Arcturus in Bootes but passes into Virgo on the 14th. In the latter part of the month with no moonlight to hinder our view, binoculars or a small telescope could be used to spot Comet Johnson as it move across Virgo. It is expected to reach magnitude +6 so should be easily visible with binoculars. The chart shows its position during the month.
June 3rd and 16th: The Alpine Valley.These are two good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the terminator is the Appenine mountain chain that marks the edge of Mare Imbrium. Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image a thin rill runs along its length which is quite a challenge to observe. Over the next two nights the dark crater Plato and the young crater Copernicus will come into view. This is a very interesting region of the Moon!
Southern Hemisphere
Claire Bretherton tells us what we can see in the southern hemisphere night sky during June 2017.

The PlanetsIntroduction
Kia ora and welcome to the June Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
This month, we reach our winter solstice here in the southern hemisphere, when the south pole of the Earth is at its greatest tilt away from the Sun. This means that the Sun appears much lower in the sky, our days are shorter and colder, and our nights are longer.
This year the solstice falls on the 21st June NZST. Whilst always around this time, the actual date of the winter solstice can sometimes fall on the 22nd. This is because it takes the Earth approximately 365 and a quarter days to go around the Sun, but we don't count that extra quarter day in our calendars every year, we save them up for a leap year. So the timing of the solstice slips around 6 hours later each year until we add an extra day and it jumps back to the beginning again.
The word solstice means "Sun stopped" or "Sun still", because the Sun rises and sets at it most northerly points of the year. As we move back towards the summer, the Sun will gradually rise and set further and further south until it stops again at the summer solstice in December, and begins the long journey back north.
HighlightsStars
Whilst the cold weather at this time of year may not be so welcome, the long, dark nights provide a perfect opportunity to observe our beautiful southern skies.
We are very lucky here in the southern hemisphere, that we have a perfect view towards the central bulge of our Milky Way galaxy, so it appears broader and brighter across our sky. The center lies towards the constellations of Sagittarius, the archer, and Scorpius, the Scorpion, which is now midway up our eastern evening skies. Scorpius is our winter constellation, and together with Sagittarius, a little below, will be dominating our skies over the next few months.
At the heart of the Scorpion is the bright orange tinged star Antares, a red supergiant with a radius nearly 900 times that of the Sun. The name Antares means "rival of Mars" because of its distinctive colour, which tells us that it is a cooler star, at around 3 and a half thousand degrees. Antares lies around 550ly away and is amongst the 20 brightest stars in the nighttime sky.
To the left of Antares is a line of stars now forming the Scorpion's claws, and further left still the faint zodiac constellation of Libra, the scales. Libra's two brightest stars form an almost vertical line in our evening sky, and have perhaps the best names of any I have seen, Zubenelgenubi and Zubeneschamali.

Zubenelgenubi, the higher of the two, is half way between Antares and Spica at a distance of around 77 light years. At magnitude 2.7 it enjoys the alpha designation, despite being slightly fainter than its beta counterpart below, probably because it lies just a third of a degree from the ecliptic.
Using binoculars you'll see that Zubenelgenubi is in fact a double star with two components separated by around 5400 AU (a little under 4' on the sky), and which appear to be co-moving through space. Strictly speaking, the name Zubenelgenubi now only refers to the brighter of the two. Both components are spectroscopic binary stars in their own right, and there may be also be a fifth component to the system, KU Librae, located 2.6 degrees away.
Below Alpha Librae is the slightly brighter Beta Librae, or Zubeneschamali, at magnitude 2.6, which lies 185 lightyears away. Zubeneschamali is a hot blue main sequence star some 130 times more luminous than the Sun, and with twice the surface temperature. Whilst stars of this type are often seen as white or bluish in colour, Zubeneschamali has often been described as greenish by observers, the only green star visible to the naked eye. Whilst theoretically this is not possible, scientists are still unsure why so many observers claim to see it this way.
Constellations
Whilst today these stars are part of Libra, the names Zubenelgenubi and Zubeneschamali derive from the Arabic for the southern claw and northern claw of the scorpion, referring back to the ancient Greeks who saw these stars as part of the constellation of Scorpius.
The idea of scales or a balance can be traced back to the ancient Babylonians though, some 4,000 years ago, at a time when the northern hemisphere autumnal equinox (where the Sun crosses the equator from the northern to southern hemisphere) appeared in that part of the sky. The choice of scales likely relates to the balance between light and dark, with equal hours of day and night experienced at the equinox, as well as the change of seasons from summer to winter, and therefore hot to cold.
The romans revived the idea, seeing Libra as the Scales of Justice held by Astraea, the Starry Goddess, represented by the neighboring zodiac constellation of Virgo. Virgo is currently home to bright Jupiter, sat a little to the left of the constellations brightest star Spica, high in the northeast after dark.
Below Scorpius is our second evening planet, cream-coloured Saturn, shining at magnitude 0 this month. Saturn reaches opposition on the 15th, when it will be directly opposite the Sun in the sky and overhead at midnight. Saturn will also be at its closest to Earth around this time making it appear at its largest and brightest, although in practice any difference will be hard to spot with the naked eye. Do take a look through a small telescope if you get a chance though. This opposition its rings will be almost at maximum tilt, so should be a wonderful sight.
Here in New Zealand, we don't have Scorpions, so we see Scorpius as something a little more familiar in the Southern Pacific. To Maori this group of stars is known as Te Matau a Maui, the fishhook of Maui, which he used to pull a great fish out of the ocean that became the north island of New Zealand, te Ika a Maui. Antares is known as Rehua, and represents a drop of blood that Maui took from his nose to use as bait.
This constellation was an important aid for ancient pacific navigators as it travels directly overhead from our latitude. Once te Matau a Maui was right overhead it was simply a case of travelling east or west to find Aotearoa/New Zealand.
By just before sunrise Scorpius or Te Matau a Maui has moved to the west south western horizon, with the hook pointing upwards.
The morning skies at this time of year are particularly important here in New Zealand as this is the time we celebrate Matariki, or Maori New Year. The timing of this celebration is based on the heliacal rising of the small group of stars known as Matariki or the Pleiades.
Opposite Scorpius in the morning sky is his arch enemy, Orion the hunter, rising directly east, with the three bright stars of his belt lying along the horizon. These are also known as Tautoru here in New Zealand.
If you follow these stars along the horizon to the right they point to Sirius or Takurua, the brightest star in the night time sky. Follow them to the left and you first come to a v shape forming the head of Taurus the bull, with the bright star Aldebaran marking his eye, and then to Matariki rising in the east north east.
The Pleiades is, in fact, visible throughout most of the year, but is only known as Matariki around this time. It disappears from our evening skies around April each year before reappearing in the morning in early June. It is this reappearance, or heliacal rising, that tells us that the old year is coming to an end. The next new moon (or for some iwi the next full moon) marks the beginning of the New Year. This year the new moon falls on the 24th of June, and may be visible a day or two after this, so Matariki will officially be celebrated on the 25th of the month.
Maori mythology
In Maori mythology Matariki, Tautoru, Takurua and Rehua form four pou, or pillars that hold Ranginui, the sky father, in the sky. Matariki supported one of Rangi's shoulders and marks the rising point of the Sun at the winter solstice. Takurua (Sirius) supports the other shoulder and is the closest bright star to the Sun's rising point at the summer solstice. These two stars represent the extent of the Sun's movement throughout the year.
Tautoru held Rangi's neck and marks the celestial equator which runs along the length of Ranginui's backbone. Poutu-te-rangi or the star Altair, marks the other end. Over in the west Rehua, or Antares, supports Ranginui's lower torso. A line drawn from Matariki to Rehua marks the ecliptic; the pathway of the Sun, Moon and planets through the sky.
These four pou form the basis of a celestial compass, a map of the night sky that was used to navigate the Pacific Ocean and bring our ancestors to Aotearoa. Today Matariki is a chance for all New Zealanders to unite in celebration of this great land we all call home: its a chance to reflect on the state of the planet we live on and the bounty that we receive from Mother Earth, to celebrate our shared history and to reflect on our very unique place in the Universe.
Nga mihi o Te Tau Hou ki a koutou katoa
Wishing you all a very Happy New Year from the team here at Space Place.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for May 2017
14 touko 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during May 2017.
The Stars and GalaxiesThe PlanetsJupiter
came into opposition on April 7th so, this month, transits in the late evening and is visible rising in the east at dusk. It is moving in retrograde motion lying in Virgo initially some 9 degrees over to the right of its brightest star, Spica. This increases to ~11 degrees as May progresses. The size of Jupiter's disk decreases slightly from 43.5. to 40.8 arc seconds during May with its magnitude reducing very slightly from -2.4 to -2.3. With a small telescope one should be easily able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Galilean moons as they weave their way around it.Saturn
rises around 11:30pm BST as may begins and will be highest in the pre-dawn sky at ~4am BST. By the end of May it will rise at ~9:30pm BST and transit at around 2am BST. Lying in the western part of Sagittarius, its diameter increases from 17.8 to 18.3 arc seconds during the month as it brightness increases slightly from magnitude +0.3 to +0.1. It will be high enough in the south-east in the hours before dawn to make out the beautiful ring system which, at over 26 degrees to the line of sight, are nearly as open as they ever become. If only it were higher in the ecliptic; its elevation this year never gets above ~18 degrees and so the atmosphere will hinder our view of this most beautiful planet. [Note: I have acquired a ZWO Atmospheric Dispersion Corrector which uses two contra-rotating prisms to combat the dispersion of the atmosphere at low elevations. If imaging Saturn (or Jupiter), Registax 6 has a tool to align the red, green and blue colour images to largely remove the dispersion from the image.]Mercury
is lost in the glare of the Sun this month so cannot be observed.Mars
lies in Taurus initially making a shallow triangle with Aldabaran to its lower left and the Pleiades cluster to its lower right. In early May, Mars has an elevation of ~11 degrees above the western horizon at sunset, but this reduces to ~5 degrees by month's end when Mars will be lost in the Sun's glare. It will then be lost from view all summer as it passes behind the Sun. By month's end it will lie some 6.5 degrees over to the left of Alnath, Beta Tauri. Its brightness falls slightly during the month from magnitude +1.6 to +1.7 whilst its angular diameter falls from 3.9 to 3.7 arc seconds. No details would be expected to be seen on its salmon-pink surface.Venus
rises in the east in the morning twilight on the first of the month and then climbs a little higher each morning as May progresses. On May 1st, the disk, forming a crescent 38 arc seconds high, is just 27% lit shining with a magnitude of -4.7 - its maximum brightness. By the end of the month, Venus shines at magnitude -4.5 with its angular size reduced to 25 arc seconds and its illuminated fraction increased to 48%. It is then close to its greatest elongation from the Sun of 46 degrees which it will reach on June 3rd. But, due to the shallow angle that the ecliptic makes to the horizon at this time of the year, it will then only have an elevation of ~16 degrees at sunrise.Highlights
JupiterThis is a great month to observe Jupiter which came into opposition on April 7th so, during May, will be visible in the south during the evening. It is moving down the ecliptic and lies in Virgo. It now reaches an elevation of ~36 degrees when crossing the meridian. An interesting observation is that the Great Red Spot appears to be diminishing in size. At the beginning of the last century it spanned 40,000 km across but now appears to be only ~16,500 Km across - less than half the size. It used to be said that 3 Earths could fit within it, but now it is only one. The shrinking rate appears to be accelerating and observations indicate that it is now reducing in size by ~580 miles per year. Will it eventually disappear?
May: Look for the Great Red Spot on JupiterA list gives some of the best evening times during May to observe the Great Red Spot which should then lie on the central meridian of the planet. The times are in UT.
May 4/5th - after midnight: The Moon occults the double star 49 LeonisJust after 00:20 BST, the dark limb of the Moon will occult the double star 49 Leonis (magnitudes +5.8 and +7.9 separated by 2 arc seconds). As a result, the starlight will take longer to be extinguished than from a single star. If the seeing were good, it might be possible to split the pair using a high magnification and see each component disappear.
May 5th and 6th before dawn: The Eta Aquarid Meteor ShowerThe Eta Aquarids are one of the finest meteor showers that can be seen from the southern hemisphere, but, in the northern hemisphere, may be glimpsed in the pre-dawn sky in the south-east around 90 minutes before dawn. Sadly, this year the peak is when the Moon is coming towards full - but happily low on the western horizon - so there will be some moonlight to hinder our view.
May 7th - evening: The Moon and JupiterThis evening the Moon, three days before full, will pass just 1.5 degrees above Jupiter.
15th May - evening: Observe the Galilean Satellites.If clear on the evening of the 15th and using a small telescope, one could observe the 4 Galilean Moons lined up on one side of the giant planet.
22nd May - dawn: Venus and a thin crescent MoonBefore dawn on the 22nd, Venus will be seen over to the left of a very thin waning crescent Moon.
22nd to 31st May - all night: Observe Comet 2015 V2 (Johnson)During the last 10 days of May, with no Moonlight to hinder our view, binoculars or a small telescope could be used to spot Comet Johnson as it moves down through the constellation Bootes closing in on the bright star Arcturus. It might reach magnitude +6 so should be easily visible with binoculars. The chart shows its position during this time.
27th May - ~23:20 BST: a shadow transit of Jupiter.After sunset on the last three day of the month, one can observe, if clear, a thin waxing crescent Moon passing the Beehive cluster (M44) as it moves up to pass Regulus, in Leo, on the 31st.
May 3rd and 16th, evening: The Hyginus RilleThese evenings, should it be clear, are a superb time to view the Hyginus Rill as it will lie close to the terminator. For some time a debate raged as to whether the craters on the Moon were caused by impacts or volcanic activity. We now know that virtually all were caused by impact, but it is thought that the Hyginus crater that lies at the centre of the Hyginus Rille may well be volcanic in origin. It is an 11 km wide rimless pit - in contrast to impact craters which have raised rims - and its close association with the rille of the same name associates it with internal lunar events. It can quite easily be seen to be surrounded by dark material. It is thought that an explosive release of dust and gas created a vacant space below so that the overlying surface collapsed into it so forming the crater.
Southern Hemisphere
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during May 2017.
Kia ora and welcome to the May Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
Our evening skies this month are dominated by Jupiter and Saturn, along with some of our brightest stars. Jupiter will be one of the first objects to appear, visible in the north east shortly after the Sun has set. A bright waxing gibbous moon will pass within 2 degrees of the planet on the evening of May 8th, that’s 4 moon diameters apart. Both will be visible within the same binocular field of view.Just to the right of Jupiter is Spica, the brightest star in the constellation of Virgo, and below, just above the horizon is orange coloured Arcturus, which at magnitude −0.05 is the brightest star in the northern celestial hemisphere and the 4th brightest in the night sky.
Arcturus has a similar mass to the Sun, but it is further along in its lifespan and has already expanded to become a red giant, with 25 times the diameter and 170 times the luminosity of our own star. When close to the horizon it often appears to twinkle red and green as its light is broken up by our atmosphere.
All three of the brighter stars are in the southern hemisphere, and are also visible in our evening skies this month. The brightest, Sirius , sits halfway up the western sky at the beginning of the month, with Orion’s belt, now almost vertical, below. Rigel and Betelguese , the seventh and ninth brightest stars sit to either side of the belt. Both Orion and Sirius will soon be disappearing from our evening skies, before reappearing before the Sun in the morning skies over the coming months.
The second brightest star Canopus is circumpolar here in New Zealand, never dropping below the horizon. This month it sits a little higher than Sirius, further around towards the south west. To complete the trio, the third brightest star, Alpha Centauri is high in the southeast, pointing the way to the Southern Cross.
Below Alpha Centauri, rising in the twilight sky is the curve of stars making the body of Scorpius, the scorpion. Its brightest star Antares is a variable star, which ranges in brightness from magnitude 0.6 to 1.6, and is on average the 15th brightest in the night sky. Antares is a red supergiant, , one of the largest stars known, almost 900 times the diameter of the Sun. If it were placed at the centre of the Solar System, its surface would extend to the middle of the asteroid belt. The name Antares means rival of Mars, because of its striking red colour. To Māori the star is known as Rehua and represents a drop of blood Maui pulled from his nose to bait his fishhook. In Aotearoa, the constellation of Scorpius in seen as Maui’s hook, te Matau a Maui, which was used to pull up a great fish which became the north island of New Zealand.
Scorpius/te Matau a Maui is our winter constellation and will be dominating our skies over the coming months, visible throughout the night.
Sitting just 1.3 degrees to the west of Antares, and visible in the same wide field telescope view, is the 5.9 magnitude globular cluster Messier 4, just about visible to the naked eye in a clear, dark sky. M4 is one of the nearest globular clusters in the sky, at just 7,200 lightyears away and is the only globular cluster that Messier was able to resolve with the modest equipment he was using, 20 years before William Herschel was able to resolve all of the Messier globular clusters with his much larger telescopes.
M4 is one of the loosest, most open globular clusters and features a central bar of 11th magnitude stars, which can be resolved in a 10cm telescope. Through binoculars the cluster is seen as a round hazy patch.
Messier 4 contains some of the oldest stars known in our galaxy, with an estimated age of 13 billion years. Discovered by the Hubble Space Telescope in 1995, these White Dwarf stars are the remnants of ancient solar like stars that have already shed their outer layers into space.
In 2003 a planet was discovered orbiting one of these White Dwarfs and its Pulsar companion, the first circumbinary (ie orbiting both stars)”planet ever found, and the first planet detected in a globular cluster. With a mass of around 2.5 Jupiters and an estimated age of 12.7 billion years, it is also one of the oldest known extrasolar planets, earning it the unofficial nicknames “Methuselah” and “The Genesis Planet”.
A little over half way from Antares to Arcturus is another globular cluster, M5, or NGC 5904, in the constellation of Serpens. At almost 6th magnitude it is also tough to spot with the naked eye in anything but the darkest conditions, but with binoculars it is easy to find, although you will need a small telescope to begin to resolve it and start to pick out a slightly elongated shape and a few edge stars.
With a calculated age of around 13 billion years, M5 is one of the oldest globular clusters known, and at 165 light years in diameter and containing hundreds of thousands of stars, it is also one of the largest. It also contains 105 known variable stars, with the brightest and most easily observed, Variable 42, changing from magnitude 10.6 to 12.1 in just under 26.5 days.
To find M5 you can star hop from the faint star 109 Virginis to 110 Virginis and then around twice the distance again to find 5 Serpentis, and M5 is just 20' to the North West.
Below Antares, and rising a little later in the evening, is bright, cream coloured Saturn. It’s a great time to observe Saturn through a small telescope at the moment with its rings at close to maximum tilt. Saturns largest moon , Titan, can be spotted orbiting around for ring diameters from the planet, with several smaller, closer moons also visible in larger telescopes.
In the morning sky Venus rises in the east around 4am and is joined by Mercury around an hour and a half before sunrise. Mercury reaches its greatest elongation west on the 18th of May and is making its best morning appearance of the year, rising before twilight begins throughout the month.
If you’re out planet spotting in the early hours then take a look for the eta aquarids meteor shower, which peaks around the 6th of May. This shower is caused by the Earth passing through the trail of debris left behind by the famous comet Halley. The shower appears to radiate from a point near the fourth magnitude star Eta Aquarii, one of the brightest in the zodiac constellation of Aquarius, representing the water bearer.

The radiant won’t rise in the eastern sky until around 2am here in New Zealand, so the best time to go meteor spotting is in the few hours before sunrise. At the shower’s peak you may be able to spot up to a meteor a minute, many of them fast and bright and leaving glowing trails behind them. Viewing conditions this year will be much better than last, with the Moon setting on the other side of the sky in the early hours of the morning, giving you a good few hours of observing time before the Sun rises just after 7 am.
You may also have a chance for some binocular comet hunting this month as Comet PanSTARRS (C/2015 ER61) heads towards Perihelion (its closest approach to the Sun) on the 10th of May. At the start of the month it will be moving from Aquarius through to Pisces and may be visible with binoculars in our morning skies. On 4th April the comet experienced an outburst, brightening from 8th to 6th magnitude almost overnight, and whilst it is always hard to predict how bright a comet is going to get, this one is definitely worth keeping an eye on.Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for April 2017
1 huhti 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during April 2017.
The Stars and GalaxiesConstellations and Stars
Orion setting in the west, with upper part of Taurus and the Pleiades still visible. Also above Orion Gemini is visible with the stars Caster above and Pollux below. Also below Gemini is Procyon the only bright star in Canis Minor. Leo is visible in the south with a wonderful region called the Realm of the Galaxies just behind the tail. Between Leo's tail and the bright star Arcturus (in Bootes) is Virgo and Coma Berenices with many Messier objects in that region. High overhead is Ursa Major with the Plough. The central star of the handle, Mizar, is a double star (with Alcor) and observable in a telescope is faint red star up to the right of the pair.
The PlanetsJupiter
comes into opposition on April 7th, lying in Virgo initially some 6 degrees above its brightest star, Spica. Visible all night, It will be due south at an elevation of 34 degrees at around midnight UT. The size of Jupiter's disk decreases slightly from 44.2 to 43.6 arc seconds as February progresses with its magnitude reducing very slightly from -2.5 to -2.4. With a small telescope one should be easily able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Galilean moons as they weave their way around it.Saturn
rises around midnight (UT) and will be highest in the pre-dawn sky. Lying in the western part of Sagittarius, its diameter increases from 17 to 18 arc seconds during the month as it brightness increases slightly from magnitude +0.4 to +0.3. It will be high enough in the south-east in the hours before dawn to make out the beautiful ring system which, at over 26 degrees to the line of sight, are nearly as open as they ever become. If only it were higher in the ecliptic; its elevation this year never gets above ~18 degrees and so the atmosphere will hinder our view of this most beautiful planet. [Note: I have just acquired a ZWO Atmospheric Dispersion Corrector which uses two contra-rotating prisms to combat the dispersion of the atmosphere at low elevations.] Mercury
passed through superior conjunction on March 7th and, on April 1st, will lie ~14 degrees above the western horizon at nightfall when it is at its greatest elongation, some 19 degrees, from the Sun. Then at magnitude -0.2, it brightness drops to magnitude +3 by the 18th of the month as it falls back towards the Sun. Mercury passes through inferior conjunction on the 20th and will reappear in the predawn sky by the end of the month. With an angular size of to 7.5 arc seconds on the 1st, increasing to 11 arc seconds on the 18th, no details would be expected to be seen on its disk.Mars
As April begins, Mars lies in Aries but moves into Taurus on the 12th of the month. In early April, Mars has an elevation of ~20 degrees above the western horizon at sunset, but this reduces to ~11 degrees by month's end. On the 16th, it lies 4 degrees below the Pleaides cluster and then passes between the Pleiades and Hyades clusters on the 25th when it lies some 9 degrees to the right of Aldebaran. Its brightness falls slightly during the month from magnitude +1.5 to +1.6 whilst its angular diameter falls from 4.2 to 3.9 arc seconds. No details would be expected to be seen on its salmon-pink surface.Venus
rises in the east about an hour before sunrise on the first of the month and then climbs a little higher each morning as April progresses. On April 1st, the disk, forming a slender crescent nearly one arc minute tall, is just 2 percent lit shining with a magnitude of -4.2. By the end of the month, Venus has its maximum brightness of magnitude -4.7 with its angular size reduced to 39 arc seconds and its illuminated fraction increased to 26 percent. It will then have an elevation of ~13 degrees at sunrise. In daytime when still high in the sky it can be imaged in the infrared as the blue light from the sky is filtered out.Highlights
April - a great month to view Jupiter.This is a great month to observe Jupiter which comes into opposition on April 7th. It is moving down the ecliptic and, at the start of April, lies in Virgo some 6 degrees above Spica (Alpha Virginis). It now reaches an elevations of ~36 degrees when crossing the meridian. An interesting observation is that the Great Red Spot appears to be diminishing in size. At the beginning of the last century it spanned 40,000 km across but now appears to be only ~16,500 km across - less than half the size. It used to be said that 3 Earths could fit within it, but now it is only one. The shrinking rate appears to be accelerating and observations indicate that it is now reducing in size by ~580 miles per year. Will it eventually disappear? The features seen in the Jovian atmosphere have been changing quite significantly over the last few years - for a while the South Equatorial Belt vanished completely but has now returned to its normal wide state.
April: Look for the Great Red Spot on JupiterThe night sky page gives a list of some of the best evening times during April to observe the Great Red Spot which should then lie on the central meridian of the planet. The times are in UT.
1st to 7th April - early evening after dusk: Mercury at its highest in the skyIf clear on the evenings of the first week of April, Mercury will be seen above the western horizon after sunset. Then it will have an elevation of some 18 degrees - so an excellent week to observe a somewhat elusive planet.
April 7/8th - all night: The waxing Moon closes on Regulus in LeoDuring the darkness hours of the night of the 7/8th of April, a waxing Moon closes on Regulus and is within 2 degrees as dawn approaches on the 8th.
10th April - all night: The Moon, one day before full, passes Jupiter in Virgo. If clear on the evening of the 10th and looking first to the south-east, one will see the Moon, one day before full, passing just 2 degrees above Jupiter in Virgo.
22nd April - after midnight: The peak of the Lyrid Meteors. Without any moonlight to hinder our view and from a dark rural location one, if clear, would have a chance of observing the peak of the Lyrid meteor shower with up to 10 meteors visible each hour. As one might expect, the shower's radiant is close to Vega in Lyra.
25th April - 1 hour after sunset: Mars passes between the Hyades and Pleiades Clusters. Looking low in the west after sunset on the evening of the 25th, Mars will be seen to lie directly between the Hyades (to its left) and Pleiades clusters - if clear, a nice photographic opportunity.
April 28th - a daylight occultation of AldebaranBefore dusk on the evening of the 28th, Aldebaran is occulted by a very thin crescent Moon. It will disappear behind the Moon's dark limb at 19:11 BST as seen from London and 19:07 BST as seen from Edinburgh and reappear at the bright limb at 20:07 BST as seen from London and 19:57 BST from Edinburgh. As darkness falls, Aldebaran will be seen to lie just below the Moon.
March 5th and 18th: An interesting valley on the Moon: The Alpine ValleyThese are two good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the limb is the Appenine mountain chain that marks the edge of Mare Imbrium. Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image is a thin rill runs along its length which is quite a challenge to observe. The dark crater Plato will also be visible nearby. You may also see the shadow cast by the mountain Mons Piton lying not far away in Mare Imbrium. This is a very interesting region of the Moon!
Southern Hemisphere
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during April 2017.
Kia ora and welcome to the April Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
New Zealand daylight saving ends the first weekend of the month, bringing our southern hemisphere summer abruptly to an end. On the bright side, the lighter mornings and darker nights will make it much easier to get out and do some observing.
One of the first objects you'll see in the evening twilight is bright golden Jupiter, rising in the east soon after the sun sets at the beginning of the month. It slowly crosses the sky through the course of the night, before disappearing in the west at sunrise. By the end of the month it will be rising well before dusk. Jupiter reaches opposition on April the 8th, meaning it will lie directly opposite the Sun in the sky and be overhead at midnight. At this time Jupiter is also at its closest to Earth, but the difference in angular size and brightness is not really noticeable to the naked eye.
Jupiter is always worth a look through a small telescope or good binoculars, revealing up to four of its large Galilean moons. The full Moon passes close to Jupiter on the 10th/11th of the month.
Jupiter sits in the constellation of Virgo, just to the left of the brightest star Spica. Last month I mentioned that Virgo is home to the Virgo Cluster of Galaxies, containing up to 2000 members. This month we'll take a closer look at some of those galaxies in more detail.
The cluster's centre lies around 54 Million light years away and it extends nearly 8 degrees across the sky. Many of the brighter galaxies are included in Messier's catalogue of non-cometary fuzzy objects and are easily visible with a small telescope. Perhaps the most famous member is the giant elliptical galaxy Messier 87, located close to the cluster centre. The second brightest galaxy in the northern part of the cluster, with an apparent magnitude of 9.59, M87 is easily observed with a modest 60mm telescope, and is in reach of a good pair of binoculars under excellent conditions, visible as a faint, hazy patch of light. Small telescopes may reveal the galaxy's elliptical shape, brightening towards the centre.
M87 is one of the most massive and luminous galaxies in the local Universe, estimated to contain the mass of around 2.7 trillion Suns, some 200 times that of the Milky Way, but only around one sixth of this mass is in the form of an estimated 1 trillion stars. It is also distinctive for its large number of globular clusters, with over 6 times as many as our own Galaxy. Close to its core is a 3.5 billion solar mass black hole, one of the most massive known, orbited by a fast moving disk of ionized gas, which is a strong source of radiation, particularly at radio wavelengths. In fact M87 is one of the brightest radio sources in the sky.
In 1918 American astronomer Heber Curtis detected a "curious straight ray" extending from the galaxy's centre, which we now know is a jet of energetic plasma blasted out from the nucleus of M87 at relativistic speeds. The central black hole of M87 is actually offset from the core by around 25 parsecs in the direction opposite to the jet, suggesting that the jet may be responsible for accelerating the black hole away from the galaxy's centre. An alternative theory suggesst that the displacement my have been caused by a merger with another galaxy.
To find M87, draw a line from Denebola at the tail of Leo to Vindemiatrix (or Epsilon Virginis), and the galaxy can be found just over half way along, close to Virgo's border with the Coma Berenices constellation.
Around 1.5 degrees back towards Leo is the M84/M86 galaxy pair, located just 17 arcminutes apart. Whilst M86 can be seen in 10x50 binoculars under good conditions, larger binoculars or a small telescope will be needed to pick up its companion easily. The two are visible in the same field of view, and in a 20cm or larger telescope a number of fainter galaxies can be seen nearby, including NGC 4435, NGC 4388, NGC 4402 and NGC 4438.
M86 and M87 are thought to be moving towards each other for their first galactic encounter.
The brightest galaxy in the cluster is the 9.4 magnitude Messier 49, located a little above M87 in our evening skies. M49 was the first member of the Virgo cluster to be found, and only the second galaxy to be discovered outside our local group. Messier 49 is interacting with the nearby dwarf irregular galaxy UGC 7636, which has a trail of debris covering 1 x 5 arcminutes of the sky.
M49 can be seen in large binoculars and small telescopes, with slightly larger telescopes picking up a bright core and large halo, but an otherwise featureless view.
Further around to the north in our evening sky, to the other side of Denebola is the main body of Leo, with the constellations brightest star Regulus or Alpha Leonis marking the lion's heart. Regulus is at the top of an upside down question mark as we see it here in New Zealand, which marks the head and mane of the Lion. With an apparent magnitude of 1.35, the star is the 21st brightest in the night sky, but it is in fact a system of four individual stars arranged in two pairs.
Regulus A is a spectroscopic binary comprising of a hot, young, blue-white main sequence star with a tiny companion of less than 0.3 solar masses, which is probably a white dwarf. Regulus B and C make a second pairing located 177 arc-seconds away from Regulus A. Resolving the BC pair from Regulus A is a good challenge for binocular observers, and certainly achievable with a small telescope.
A little below Regulus is another well known double star called Algieba or the Mane. First discovered by William Herschel in 1782, Algieba comprises a yellow-orange giant primary and a yellow-white giant secondary at magnitudes 2.3 and 3.5 respectively. The pair have an angular separation of around 4 arcseconds, so you won't be able to resolve them in binoculars, but with a telescope of aperture around 8cm or greater you should be able to split them.
Like its neighbouring Virgo, Leo is also home to a number of bright galaxies including the Leo Triplet, a small group of interacting galaxies consisting of spiral galaxies M65, M66 and NGC 3628. Often known as the M66 group, the Leo Triplet is located around 35 million light years away, and provides a fantastic opportunity to study galaxy interaction in our local Universe. Each of the three main members show signs of tidal disturbance with NGC 3628 exhibiting an impressive tidal tail extending for over 300,000 light years.
The triplet is located fairly close to Denebola, or Beta Leonis and around half way between Chertan, or Theta Leonis and Iota Leonis. Most small telescopes should be able to pick up the group, but M66, the brightest of the three, and M65, the second brightest, should also be visible in large binoculars.
This month the new moon falls on the 27th, so around this time will be the best opportunity for galaxy spotting.
Moving around towards the southeast, our winter constellation of Scorpius is rising in our evening skies at the beginning of the month and by around 11pm is joined by cream-coloured Saturn, sat a little below. By the end of the month Saturn will be rising shortly after 8pm. The Moon will be just to the left of Saturn on the night of the 16th.
Venus is moving quickly into our morning skies, rising a little over an hour before the Sun at the start of the month and 3 hours before at the end, when it will be joined in the dawn skies by faint Mercury sat lower and to the right of bright Venus.
Wishing you clear skies, and happy galaxy hunting, from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for March 2017
1 maalis 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during March 2017.

Highlights of the Month
1st-4th March - after sunset: Three planets and (on the 1st) a very thin crescent Moon. On these nights, Venus is 12 degrees down to the lower right of Mars, both in the southwest, and between them lies Uranus. On the 1st of March, they will be joined by a very thin waxing crescent Moon.
March 4th, following 10pm: The Full Moon occults Gamma Tauri in the Hyades cluster. During the late evening, the first quarter Moon will occult the star Gamma Tauri, which forms the peak of the triangular shaped Hyades Cluster. In North America, the Moon can be seen occulting Aldebaran.
10th March - all evening: The Moon, two days before full, passes just below Regulus in Leo.
March 15th - before dawn: The Moon lies close to Jupiter and Spica. Before dawn, Jupiter appears between the Moon to its upper left and Spica, Alpha Virginis, down to its lower left.
March 20th - before dawn: Saturn near the third quarter Moon. Before dawn on the 20th and looking South, Saturn will be seen over to the right of the third quarter Moon.
March 6th and 19th: The Alpine Valley. These are two good nights to observe an interesting feature on the Moon with a small telescope. Close to the limb is the Appenine mountain chain that marks the edge of Mare Imbrium. Towards the upper end is a cleft called the Alpine Valley. The dark crater Plato will also be visible nearby.

The PlanetsJupiter, moving towards opposition on April 7th, lies in Virgo initially some 4 degrees above its brightest star, Spica. With a small telescope, it should be easy to see the equatorial bands in the atmosphere, sometimes the Great Red Spot, and up to four of the Gallilean moons.

Saturn rises well after midnight and will be highest in the pre-dawn sky. It will be high enough to make out the beautiful ring system which, at over 26 degrees to the line of sight, are as open as they ever become. Its elevation this year never gets above 18 degrees, so the atmosphere will hinder our view of this planet.

Mercury passes through superior conjunction on March 7th and becomes visible around the 15th in bright twilight just above the western horizon. On the 19th, on its way up, it passes Venus, on its way down, some 9 degrees to its right.

At the beginning of March, Mars can be found in Pisces up and to the left of Venus. As the month progresses, Mars continues to move eastwards (moving into Aries on the 8th) whilst Venus falls back towards the western horizon.

Venus starts the month dominating the western sky, shining virtually at its brightest with a magnitude -4.8. It lies due south in mid-afternoon and can even by seen with the unaided eye. After dark in a very dark location, it can even form shadows. On the 1st of February, it has its highest elevation at sunset during the month at ~30 degrees. But then, as the month progresses, it falls back towards the Sun and passes in front of it on the 25th. Very unusually, Venus is far enough north of the Sun that it will start rising before dawn on March 15th, some 10 days before inferior conjunction. Thus it could be seen both at nightfall and at dawn for a few days.
 
Southern Hemisphere
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during March 2017.
As we approach the autumn equinox on the 20th of March, our evenings are quickly drawing in, we have more time to get outside observing our beautiful Southern skies. The Milky Way, or te Ika Roa arches high across the sky from north-northwest to south-southeast after dark.
Canopus, the second brightest star in our night time sky, is just to the southwest of overhead. Canopus is circumpolar from our position here and is considered to be a tapu, or sacred to Maori. Around halfway from Canopus to the southwest horizon is Achernar, a blue main sequence star around 7 times more massive than the Sun but over 3000 times more luminous. Achernar is part of a binary system, with a fainter, less massive A type companion. Achernar and Canopus form a roughly equilateral triangle with the Southern Celestial Pole. Unlike the northern hemisphere, we have no nearby bright star to mark this point, so we have to estimate it from the surrounding stars.
Not far from the southern celestial pole towards Achernar, you may be able to spot two small fuzzy patches of light, easily seen with the naked eye on a dark, moonless night. These are the Large and Small Magellanic Clouds, two small irregular dwarf galaxies that neighbour our own. Whilst these galaxies are much smaller than the Milky Way, combined they still contain billions of stars. The best time to look out for these galaxies is around the new moon on the 28th of the month, when they will be high in the south after dark.
Alpha and Beta Centauri are the first and second brightest stars in the constellation of Centaurus. The constellation, which is currently the 9th largest in the sky, once incorporated the constellations of Lupus and Crux. The globular cluster Omega Centauri, sits just to the east of the bright band of our Galaxy. This is by far the largest and brightest globular cluster in the Milky Way. The cluster is relatively easy to find even with the naked eye, appearing as a fuzzy star around 13 degrees northeast of Gamma Crucis at the top of the Southern Cross. With a small telescope the cluster becomes a glowing, shimmering ball of stars.
Further east and low on the horizon after dark is the constellation of Virgo, with its brightest star Spica rising just as twilight ends at the start of the month. Spica is actually a particular type of binary system called a rotating ellipsoidal variable, where its two components orbit so close together that they become egg-shaped rather than spherical. Virgo is also home to the Virgo Cluster of galaxies, containing perhaps as many as 2000 members. Just below and to the left of Spica this month is bright, golden Jupiter. With a decent pair of binoculars, you should be able to pick out Jupiter's four largest moons. The nearly full moon will pass close by on the 14th and 15th of the month.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for February 2017
11 helmi 2017· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during February 2017.
The PlanetsJupiter lies in Virgo some 3 and a half degrees above its brightest star, Spica. At the start of February it rises in the east at ~00:30 but by month's end by ~22:45. It will be due south at an elevation of 34 degrees at ~06:00 at the start and at ~04:00 by the end of February. The size of Jupiter's disk increases slightly from 39 to 42 arc seconds as February progresses with its magnitude increasing very slightly from -2.1 to -2.3. On February 6th, Jupiter halts its eastwards movement across the heavens and begins to move westwards in retrograde motion for several months. With a small telescope one should be easily able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Galilean moons as they weave their way around it.Saturn is now a morning object, rising in the south-east at ~08:00 UT as the month begin but by about 06:30 UT at its end. Lying in the southern part of Ophiuchus, its diameter increases from 15.6 to 16.1 arc seconds during the month as it shines at magnitude +0.5. Towards the end of the month it will be high enough in the south-east before dawn to make out the beautiful ring system which, at over 26 degrees to the line of sight, are as open as they ever become. If only it were higher in the ecliptic; its elevation this year will never gets above ~18 degrees in elevation and so the atmosphere will hinder our view of this most beautiful planet. [Note: I have just acquired a ZWO Atmospheric Dispersion Corrector which uses two contra-rotating prisms to combat the dispersion of the atmosphere at low elevations.]Mercury lies low in the southeast just before dawn down to the lower left of Saturn. It brightens from -0.2 to -1.2 during the month. It will be best seen around mid-month but no details would be expected to be seen on its disk which spans around 5 arc seconds across.Mars is easy to find this month lying in Pisces up and to the left of Venus. They are closest on February 1st with a separation of 5.4 degrees. By month's end, as Mars continues to move eastwards and Venus begins to fall back towards the western horizon, their separation increases to just over 12 degrees. Its brightness falls slightly from magnitude +1.1 to +1.3 whilst its angular diameter falls from 5.1 to 4.6 arc seconds. No details would be expected to be seen on its salmon-pink surface.Venus is dominating the western sky this month shining virtually at its brightest with a magnitude -4.8. Its close proximity to a crescent Moon last month was given a lot of attention! It lies due south in mid-afternoon and can even by seen with the unaided eye. After dark in a very dark location it can even form shadows! On the 4th of February it reaches its highest elevation of 33 degrees at sunset. Its angular size increases from 31 to 46 arc seconds during the month but at the same time the phase reduces from 40 percent to 18 percent illuminated. These two effects compensate each other which is why the brightness stays so constant. In visible light no details are seen on its brilliant white surface but cloud details can be seen or imaged in the ultra-violet. In daytime when still high in the sky it can be imaged in the infrared as the blue light from the sky is filtered out. This month's astronomy digest article on imaging the Moon and planets in the infrared shows how Venus looked on the 5th of January 2017.Highlights31st January to 5th February - after sunset: Venus approaches within 6 degrees of Mars If clear on the evenings of the 31st of January to the 5th of February and looking southwest one could not fail to spot Venus. But, on these nights Venus comes to within 5 degrees 23 arc seconds of Mars lying up to its left. On the 31st of January and the 1st of February, they will be joined by a thin waxing crescent Moon.5th February - all evening: The first quarter Moon occults stars within the Hyades Cluster. If clear on the evening of the 5th and looking first to the south-southeast, one will see the first quarter Moon passing in front of the Hyades cluster in Taurus. At around 18:42 its dark limb will occult the pair of stars Theta 1 and Theta 2 Tauri and at ~20:32, the magnitude 2.73 star 85 Tauri. Then at 23:27 it will lie very close to magnitude -0.7 star Aldebaran - a red giant star that lies between us and the cluster.February 11th - just before dawn: The Full Moon below Regulus in Leo Just before dawn and, given clear skies and a very low horizon towards the west, you should easily see the Full Moon lying below the magnitude 1.35 star, Regulus, Alpha Leonis.February 15th - before dawn: The Moon lies close to Jupiter If clear before dawn on the 15th and looking southwest, one will see Jupiter lying between the Moon to its upper right and Spica, Alpha Virginis, down to its lower left.February 21st: Saturn near a waning crescent Moon Before dawn on the 21st and looking south-southeast, Saturn will be seen down to the lower right of a thin waning crescent Moon.February 26th - after sunset: Uranus close to Mars with both up to the left of Venus This is an excellent chance to find Uranus - perhaps for the first time - shining at magnitude 5.9 just to the lower left of Mars at magnitude 1.3. They will be just 35 arc minutes apart so Uranus will be easily spotted with Binoculars. The turquoise disk with an angular size of just over 3 arc seconds may just be seen as such using a small telescope.Southern Hemisphere
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during February 2017.
Kia ora and welcome to the February Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.
This month we'll start to see some changes in our evening skies. Bright Venus, which has been dominating in the west for some months, is now beginning its journey back towards the Sun. Whilst still visible in the dusk skies, it will be setting as twilight ends, around an hour and a half after the Sun, at the beginning of the February, but by the end of the month it will be dropping below the horizon just 30 minutes after sunset. Fainter red Mars is a little above, holding its position well as it moves through the constellation of Pisces. At the end of the month, Mars will pass within 34 arcminutes of faint Uranus, with both visible in the same binocular field of view, and well worth a look, particularly as this also coincides with the new moon on the 27th, although by the time it gets fully dark from our location the pair will right on the horizon.
On the opposite side of the sky, golden Jupiter is now moving into our evening skies, rising just before midnight at the start of the month and by around 10pm, as twilight ends, at the end.
Orion is now high in the north after dark, with Sirius, or Takurua, the brightest star in our night-time sky, even higher.
Below and to the right, and forming a triangle with Sirius and Betelgeuse, is Procyon, the brighter of the two main stars that form the constellation of Canis Minor, Orion's small hunting dog. Procyon is the eighth brightest star in the night-time sky and, like Sirius (at ~9 ly distant), is one of our Sun's nearest neighbours at just 11 light years away. Also like Sirius, it is in fact a binary system, with a 1.5 solar mass primary and a faint white dwarf companion.
Just over a third of the way between Sirius and Procyon, in the constellation of Monoceros, is M50, a pretty, heart-shaped open cluster of stars, visible in binoculars.
Around a third of the way from Betelgeuse to Procyon is NGC2244, a rectangular cluster of stars that is embedded in a faint nebula called the Rosette. Whilst the cluster is visible in binoculars and small telescopes, the nebula is more of a challenge and is best seen photographically.
Below Canis Minor sit another pair of stars, Castor and Pollux, marking the heads of Gemini, the twins. Pollux, the higher and brighter of the two stars, is the 17th brightest star in our night sky. It is about 35 light years away from us, whilst Castor is in fact a sextuple star system located 52 light years from Earth.
Nearby to Eta Geminorum, at the foot of the twin of Castor, is the open star cluster M35, covering an area almost the size of the full moon. Under good conditions it can be seen with the unaided eye as a hazy star, but binoculars or a wide-field telescope will reveal more detail and are the best way to view this lovely cluster.
Next to Gemini is the faint zodiac constellation of Cancer, the crab. At the centre of Cancer is a lovely open cluster of stars known as M44, Praesepe (the Manger) or the Beehive. At magnitude 3.7, the cluster is visible to the naked eye as a hazy nebula, and has been know since ancient times. It was one of the first objects Galileo studied when he turned his telescope to the skies in 1609.
Galileo was able to pick out around 40 stars, but today we know that Praesepe contains over 1000 individual members, with a combined mass of between 500 and 600 times that of the Sun. As one of the closest open star clusters to our Solar System, M44 is a great target for binoculars or small telescopes, which will easily reveal a number of individual stars within it.
Higher, and to the east of Canis Major is Puppis, representing the Poop deck of the great ship Argo, which we explored last month. Inside Puppis are two lesser known Messier Objects, M46 and M47.
Messier 46 (also known as M 46 or NGC 2437) is a rich open cluster at a distance of about 5,500 light-years away. M46 is estimated to contain around 500 stars, of which around 150 of magnitude 10-13. Estimated to be only 300 million years old, this is a young cluster, and a lovely sight in binoculars or a small telescope. Astronomer John Herschel described it in his General Catalogue of Nebulae and Clusters of Stars as 'Remarkable, cluster, very bright, very rich, very large, involving a planetary nebula'. This planetary nebula, located near the cluster's northern edge, is NGC 2438.
A planetary nebula is formed when a low or intermediate mass star comes to the end of its life, ejecting its outer layers into space as a glowing shell of ionized gas.
Whilst NGC 2438 appears to lie within the cluster, it is probably just a chance line of sight effect as the vadial velocities are quite different. NCG 2438 is estimated to lie somewhat closer than M46 at around 2900 ly away.
Located around 1 degree west is another open cluster, M47. The two fit easily within one binocular field of view, and are often referred to as sisters.
Messier 47 or NGC 2422 has actually been discovered several times. The first was some time before 1654 by Giovanni Batista Hodierna and then independently by Charles Messier on February 19, 1771. William Herschel also independently rediscovered it on February 4, 1785, and it was included as GC 1594 in John Herschel's General Catalogue of Nebulae and Clusters of Stars (the precursor to Dreyer's New General Catalogue) in 1864.
Due to a sign error by Messier, the cluster was considered a 'lost Messier Object' for many years, as no cluster could be found at the position of Messiers original coordinates. It wasn't until 1959 that Canadian astronomer T. F. Morris identified that the cluster was in fact NGC2422, and realized Messier's mistake.
M47 lies at a distance of around 1,600 light-years from Earth with an estimated age of about 78 million years. M47 is described as a course, bright cluster containing around 50 stars, scattered over an area around the same size as the full moon in the sky. It is bright enough to be glimpsed with the naked eye under good observing conditions, but best viewed with binoculars or a small telescope.
There are a couple of other excellent binocular targets in Puppis, including open cluster NGC2477 - a wonderful, rich cluster of over 300 stars, described by American Astronomer Robert Burnham as 'probably the finest of the galactic clusters in Puppis' along with its neighbor NGC 2451, both located close to the second magnitude star Zeta Puppis.
Also known as Naos, this blue supergiant is one of the hottest, most luminous stars visible to the naked eye. It has a bolometric (total) luminosity of at least 500,000 times that of the Sun, but with most of its radiation emitted in the ultraviolet it is visually around 10,000 times brighter. It is also one of the closest stars of its kind to our Sun, at a distance of around 1,080 ly.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for December 2016
2 joulu 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during December 2016.
Venus below a thin crescent Moon
After sunset on December 3rd, looking low towards the south-southwest, Venus shining at magnitude -4.2, will be seen, if clear, below a very thin crescent Moon.
December 4th after sunset: Venus, Mars and a crescent Moon
If clear after sunset on the 4th, looking low towards the south-southwest it should be possible to see a thin crescent Moon to the upper left of Mars with Venus well down to its right.
December 13 before dawn: The Moon Occults Aldebaran in the Hyades Cluster
During the night of the 12th/13th December, the Full Moon will pass throught the Hyades Cluster and occult many of its stars. At around 6:15 UT on the 13th, it will occult -0.7 magnitude Aldabaran which lies between us and the cluster. This may be a grazing occultation from parts of the UK.
December 14th and 15th after midnight: the Geminid Meteor Shower
The early mornings of December 14th and 15th will give us the chance, if clear, of observing the peak of the Geminid meteor shower. Sadly, this is not a good a year as these nights are just after the Full Moon and the fainter meteors will not be seen. However, as I saw last year, the Geminids can often produce near-fireballs and so the shower is still well worth observing. An observing location well away from towns or cities will pay dividends. The relatively slow moving meteors arise from debris released from the asteroid 3200 Phaethon. This is unusual, as most meteor showers come from comets. The radiant - where the meteors appear to come from - is close to the bright star Castor in the constellation Gemini as shown on the chart. If it is clear it will be cold - so wrap up well, wear a woolly hat and have some hot drinks with you.
December 22nd/23rd - late evenings: the Ursid Meteor Shower
The late evenings of the 22nd and 23rd of December are when the Ursid meteor shower will be at its best - though the peak rate of ~10-15 meteors per hour is not that great. Pleasingly, the Moon will not affect our view during much of the night. The radiant lies close to the star Kochab in Ursa Minor (hence their name), so look northwards at a high elevation. Occasionally, there can be a far higher rate so its worth having a look should it be clear.
December 30th/ 31st after sunset: Venus closes on Mars
After sunset at the end of the month, Mars, in Aquarius will be seen to the upper right of Venus low in the south-southwest.
December 6th and 20th: The Alpine Valley
These are good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the limb is the Appenine mountain chain that marks the edge of Mare Imbrium.Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image a thin rill runs along its length which is quite a challenge to observe.Over the next two nights following the 6th the dark crater Plato and the young crater Copernicus will come into view. This is a very interesting region of the Moon!
Haritina Mogosanu from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during December 2016.
We'll start our tour in Orion, sitting high in the east after dark. Orion lies along the celestial equator, and can be seen (at least partially) throughout the world. As he was invented in the Northern hemisphere, in New Zealand we see him upside down. Orion contains a number of interesting objects to observe with both binoculars or telescopes. If you look carefully you may see the middle star of Orion's sword has a fuzzy appearance. This is the Orion Nebula, which is a stellar nursery, a huge cloud of gas and dust in which new stars are being born. In the heart of the Orion nebula is a small group of bright stars known as the Trapezium Cluster. The ultraviolet radiation from these stars is lighting up the surrounding gas. Following Orion's belt to the left we come to an upturned V shape of stars marking the head of Taurus the bull. At the bottom of this V is the bright orange star Aldebaran, at around 65ly away, representing the eye of the bull. The other stars in the V are part of the more distant Hyades cluster. At 153 ly away, the Hyades is the closest, and one of the best studied, open clusters to Earth. It is estimated to be around 625 million years old. Over time the cluster will continue to spread out and disperse into space, with some of the largest and brightest members already coming towards the ends of their lives. Following Orion's belt to the right, you can follow the band of the Milky Way around the sky, through the False and Diamond Crosses to Crux, the Southern Cross, low in the south. Sat beside the Southern Cross is a dark patch called the Coal Sack Nebula. Known as a dark nebula, the gas and dust in this cloud is blocking the light from more distant stars, obscuring them from our view. To Maori the Coal Sack Nebula is known as Te Patiki, or the Flounder. In our western skies, we see a trio of planets this month. Mercury is low on the southwestern horizon for the first half of the month, setting around an hour and a half after the sun, before sinking into the evening twilight after the 15th. Venus is higher in the west, the first thing you'll see as the sky begins to darken, and sets close to midnight. Mars is much fainter and to the top right of Venus, moving through Capricorn and into Aquarius over the course of the month The Phoenicids reach their peak on 6th December and are thought to be associated with the comet D/1819 W1 (Blanpain). With the radiant in the constellation of Phoenix, not far from Achernar, this shower is well placed for southern hemisphere observers throughout the hours of darkness. The minor Puppid-Velids meteor shower also reaches its peak at around the same time with a zenithal hourly rate of around 10. The Geminids are peaking on the 15th of the month. This is one of the best meteor showers of the year, but we are not well placed for viewing in New Zealand, with the radiant in the constellation of Gemini and well north of the equator. The constellation is at its highest around 3 am, but still appears low in our northern sky. Due to this low height we only see around half of the meteors visible to those in the northern hemisphere.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for November 2016
4 marras 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during November 2016.
The PlanetsJupiter is the only planet that can be seen in the pre-dawn sky this month rising some two and a half hours before the Sun at the start of November, but by around 2:20 UT (GMT) by the end of the month. On the first of November it will lie some 20 degrees above the south-eastern horizon an hour before sunrise and some 10 degrees higher by month's end. Though at its smallest and dimmest, it still has a magnitude of around -1.7 and shows a 32 arc second disk. It remains in Virgo throughout the month and initially lies just 2 degrees below Porrima, Gamma Virginis, and sinks slowly southwards until by month's end it lies half way between Porrima and Spica, Alpha Virginis. With a small telescope, early risers should be able to see the equatorial bands in the atmosphere and the four Gallilean moons as they weave their way around it.Saturn is still visible low in the southwest after sunset, but is only some 10 degrees above the horizon 45 minutes after sunset. However as the month progresses it will sink lower and become harder to see. It lies in the southern part of Ophiuchus some 7 degrees up and to the left of Antares in Scorpius. One could not hope for a sharp view (but I am going to try using an Atmospheric Dispersion Corrector to help) but its wide open ring system should be seen. Sadly Saturn is moving towards the southern part of the ecliptic so for quite a few years will only be seen at low elevationsMercury, shining at magnitude -0.5 and with a disk some 5 arcs seconds across becomes visible low in the southwest after sunset by the third week of November and slowly climbs higher in the sky until it reaches its furthest angular distance from the Sun in mid December. It might just be spotted close to Venus on the 23rd.Mars, moving quickly eastwards through eastern Sagittarius and Capricornus, dims from magnitude +0.4 to +0.6 during November. The red (actually salmon pink) planet can be seen low above the southern horizon throughout the month but, with a disk only about 7 arc seconds across, no surface features will be seen.Venus, in the west, sets some 2 hours after the Sun at the start of the month but an hour later by month's end as it begins to dominate the evening sky. Its brightness increases from -4.0 to -4.2 magnitudes during the month whilst the angular size of its gibbous disk increases from 14 to 17 arc seconds. As it does so its phase reduces from 78 to 70% which explains why the brightness changes so little. Venus is moving eastwards, leaving Ophiuchus on the 9th into Sagittarius where it passes over the Teapot and will be just 7.5 arc minutes below its 'lid' star, Lamda Sagittari (shining at magnitude 2.8) on the 17th.HighlightsNovember early mornings: November Meteors.
In the hours before dawn, November gives us a chance to observe meteors from two showers. The first that it is thought might produce some bright events is the Northern Taurids shower which has a broad peak of around 10 days but normally gives relatively few meteors per hour. The peak is around the 10th of November and, pleasingly, the Moon is first quarter on the 7th so, in the first week of November will have set by midnight. The meteors arise from comet 2P/Encke. Its tail is especially rich in large particles and, this year, we may pass through a relatively rich band so it is possible that a number of fireballs might be observed!
The better known November shower is the Leonids which peak on the night of the 17th/18th of the month. Sadly, the Moon will be just after full so will hinder our view. As one might expect, the shower's radiant lies within the sickle of Leo and meteors could be spotted from the 15th to the 20th of the month. The Leonids enter the atmosphere at ~71 km/sec and this makes them somewhat challenging to photograph but its worth trying as one might just capture a bright fireball. Up to 15 meteors an hour could be observed if near the zenith. The Leonids are famous because every 33 years a meteor storm might be observed when the parent comet, 55P/Temple-Tuttle passes close to the Sun. In 1999, 3,000 meteors were observed per hour but we are now halfway between these impressive events hence with a far lower expected rate.
Around the beginning and end of November (with no Moon in the sky): find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum
In the evening, the galaxy M31 in Andromeda is visible in the south. The chart provides two ways of finding it:
1) Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago!
2) You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right as shown on the chart.
Around new Moon (11th November) - and away from towns and cities - you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies. It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40 or, preferably, 10x50). Follow the two stars back from M31 and continue in the same direction sweeping slowly as you go. It looks like a piece of tissue paper stuck on the sky just a bit brighter than the sky background. Good Hunting!
November 2nd - after sunset: Venus, Saturn and a thin crescent Moon
After sunset on the 2nd and seen in the west, a thin crescent Moon will lie above Saturn (magnitude +0.5) whilst over to the lower left will lie Venus (magnitude -4).
November 5th - before sunrise: Jupiter lies below Porrima in Virgo
Around one hour before sunrise looking towards the the East-Southeast, Jupiter will be seen lying in Virgo below Porrima, Gamma Virginis, and above Spica, Alpha Virginis.
November 15th - late evening until sunrise: The full Moon close to the Hyades Cluster.
During the night, the full moon will be seen moving away to the left of the Hyades Cluster in Taurus. Lying half way towards the cluster is the red-giant star Aldebaran.
November 25th - one hour before sunrise: The third quarter Moon close to Regulus in Leo.
In the hours befor dawn, the third quarter Moon will seen lie close (just over 3 degrees) to Regulus in Leo.
Southern Hemisphere
Claire Bretherton from the Space Place at Carter Observatory in New Zealand speaks about the southern hemisphere night sky during November 2016.
Kia ora, and welcome to the November Jodcast from Carter Observatory in Wellington, New Zealand.
As Scorpius/ Te Matau a Maui sets in the west, his arch enemy, and our summer constellation, Orion rises towards the east along with Taurus and Canis Major. The bright star Antares, which marks the heart of the Scorpion, is also known as Rehua to Maori. It represents one of the four Pou, or pillars, that hold Ranginui, the sky father up in the sky. It sits just above the south western horizon at around 11pm at the beginning of the month. These four pou form the basis of a celestial compass, a map of the night sky that was used to navigate the vast oceans of our planet and bring our ancestors to Aotearoa/ New Zealand.
The other three pou are marked by Matariki (the Pleiades), Tautoru (the belt of Orion) and Takurua (Sirius), which line up along the eastern horizon. Matariki supports one of Rangi's shoulders and marks the rising point of the Sun at the winter solstice. Takurua (Sirius) supports the other shoulder and is the closest bright star to the Sun's rising point at the summer solstice. These two stars represent the extent of the Sun's movement throughout the year. In between, rising directly east, is Tautoru, or the belt of Orion, marking the rising point of the Sun at the time of the equinox.
Stretching from Scorpius around to Orion is Te Waka o Tamareriti, or Tamarereti's canoe, which lines up along the horizon in our evening sky. The front of the canoe is marked by the tail of Scorpius, with the sting representing the beautifully carved wood that adorns the prow. The star at the end of the Scorpion's curving tail marks the place where the bow meets the water, whilst the bright, orange star, Antares, marks the crest of a wave as the great waka glides through the waters of the Milky Way.
The Southern cross marks the anchor, Te Punga and the pointers, alpha and Beta Centauri are the anchor line, Te Taura. The key seasonal markers of Takurua (Sirius) and Rehua (Antares) are on either side.
Orion marks the stern of the canoe, with the elaborately carved stern post rising all the way up from red Betelgeuse to bluish Rigel. A tall mast rises from the waka all the way to Achernar, high in the south, which, at magnitude 0.46, is the brightest start in the southern constellation of Eridanus, the river, and the tenth brightest in the night sky.
A little below Achernar are two small fuzzy patches of light, the Large and Small Magellanic Clouds, which mark the waka's sails.
One story tells of Tamarereti sailing across the sky in his waka with all the stars in kete or baskets. He places the key seasonal and navigational stars in their correct positions in the sky, but finds he has lots of smaller stars left over. So he capsizes his waka spilling all the smaller stars into the sky forming Te Ika Roa, or the Milky Way. Another story tells of Tamareriti scattering bright pebbles in the dark, lightless sky to help guide his way home. The pebbles became the stars and the wake of his waka formed the Milky Way.
The sky we see in the mid-evening in October/November each year is, in fact, the same sky we see just before sunrise around June, the time we celebrate Matariki, or Māori New Year. It is said that the bright star Canopus, or Atutahi (the ariki or high chief of the heavens), pulls up the anchor at the start of the year starting the waka in motion. During the year you can track the progress of Tamarereti's waka as it moves across the sky, one day at a time.
Canopus is the second brightest star in the night time sky, with a magnitude of -0.74, and the brightest in the southern constellation of Carina. It is a white F-type supergiant with a mass around 10 times that of our Sun. It can be seen midway up the south eastern evening sky this month.
Saturn can still be found in our evening skies at the start of the month, just to the right of Antares, and setting around 9:30, but it will disappear into the evening twilight by months end. Venus starts November just above the pair, but continues to move eastwards against the background stars, rising through Sagittarius over the second half of the month. On the 17th, you'll find it right at the tip of the lid of the upside down teapot asterism. Venus will be setting around 3 hours and 20 minutes after the Sun throughout November.
Mars is higher still, and continues to hold its position well, moving from Sagittarius through Capricorn, and setting after midnight.
Mercury also makes an appearance this month. On the 20th it moves between Saturn and Antares forming a line of similar brightness "stars" along the dusk horizon, before continuing to move up away from the pair. Unfortunately, Mercury's evening appearance this month will not be as favourable as that of August this year, as Mercury will set before twilight ends.
Look out for the Leonid meteor shower, which peaks around the 17th of the month, when the Earth passes through the trail of dust and debris left behind by the comet Temple-Tuttle. Whilst normally a reliable but fairly quiet meteor shower, observers have noticed that roughly every 33 years the number of meteors observed during the shower show a marked increase as the Earth passes through the denser parts of the cometary debris trail.
Sadly, the 2016 shower is not expected to reach these high levels, with a predicted maximum of around 10-20 meteors per hour, and with a bright 18 day old Moon in the sky, there will be significant interference to hamper our viewing.
The radiant of the shower, from which the meteors appear to originate, is located in the constellation of Leo, which rises only a couple of hours before the Sun in our morning sky. The best time to observe the Leonids is about 2-3 hours before sunrise on the mornings around the peak.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for October 2016
13 loka 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the Northern hemisphere night sky during October 2016.
Highlights of the Month
October - A good month to observe Uranus with a small telescope.
Uranus comes into opposition - when it is nearest the Earth - on the night of the 15th of October, so will be seen well this month - particularly from around the beginning and end of the month when no moonlight will intrude. Its magnitude is +5.9 so Uranus should be easily spotted in binoculars lying in the southern part of Pisces to the east of the Circlet asterism and east-southeast of 4th magnitude stars Epsilon Piscium and Delta Piscium as shown on the chart. It rises to an elevation of ~45 degrees when due south. Given a telescope of 4 inches it should be possible to see that it has a disk (3.6 arc seconds across) which has a pale green-blue tint. With an 8 inch telescope and good seeing, perhaps using a green filter it may even be possible to see some detail in the planet's cloud features which appear to be more prominent than usual. That is an observing challenge! Four of its satellites, Arial(+14.4), Umbrial(+15), Titania (+13.9) and Oberon (+14.1) can also be seen given a night of good seeing and a telescope of 8 inches diameter or more.
October 3rd - after sunset: Venus and a very thin crescent Moon
As twilight fades on the 3rd of October and given clear skies and a very low horizon in the south-west you may be able to spot Venus lying down to the left of a very thin crescent Moon, just 6.7percent illuminated. This gives you a chance of observing 'earthshine', the 'dark' side of the Moon faintly illuminated by light reflected from the Earth.
October 8th, - one hour after sunset: the first quarter Moon lies above Mars
After sunset, looking south and given clear skies, the first quarter Moon will be visible lying up to the left of Mars shining at magnitude +0.15. Mars, in Sagittarius, is lying just to the left of the top star of the Teapot, Lambda Sagittarii.
Observe the International Space StationUse the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK and across the world.
Find details of sighting possibilities from your location from the location index. See where the space station is now using the tracking page.
The Planets JupiterJupiter having passed behind the Sun last month, will appear again low above the eastern horizon around the 8th of October. On the 11th, Jupiter at magnitude -1.7 lies close to Mercury but they will only be ~5 degrees above the horizon 30 minutes before sunrise. As the month progreses, Jupiter rises a little earlier so that by month's end and still at magnitude -1.7, it rises some two and a half hours before the Sun. A low eastern horizon and the use of binoculars may well be needed but please do not use them after the Sun has risen. As the Earth moves towards Jupiter, the size of Jupiter's disk increases slightly from 30.6 to 31.2 arc seconds so early risers at the end of the month should be able to observe the equatorial bands in the atmosphere and the four Gallilean moons as they weave their way around it. SaturnOn September 11th, Saturn, lying in Ophiuchus, was just 6 degrees above, and a little to the left, of Antares in Scorpius. It is moving slowly eastwards but by October's end will still be only 7 degrees distant. Saturn's brightness stays constant during the month at +0.5 whilst its angular size drops slightly from 15.9 to 15.4 arc seconds. However, the rings are almost at their most open at 26 degrees from edge on and so still make a magnificent sight. Some 20 degrees above the southwestern horizon at the start of October an hour after sunset it will fall then to just 10 degrees by month's end. This is really our last chance to observe it this apparition. MercuryMercury is just past the peak of its best morning apparition, shining at magnitude -0.8 some 8 degrees above the eastern horizon 45 minutes before sunrise. On the 11th, at magnitude -1.1 it will lie just 0.8 degrees to the left of Jupiter. Its disk then has an angular diameter of 5 arc seconds. Mercury will appear lower each morning becoming lost in the Sun's glare by mid month as it moves towards superior conjunction with the Sun on the 27th. MarsMars, lying in Sagittarius, reaches its lowest declination (-25 degrees) on October 3rd and so will be seen some 9 degrees above the south-southwestern horizon as twilight ends. Fading from magnitude +0.1 to +0.4 during October, with a disk shrinking to just 8 arc seconds across during the month it will only appear as a featureless salmon-pink object. It starts the month to the lower left of the Lagoon Nebula, M8, and, on the 6th, passes just south of the top star making up the 'Teapot', Lamda Sagittarii. In the last two weeks of October it passes over the Teapot's handle as it moves eastwards across the heavens. It lies closest to the Sun on the 29th. VenusVenus can be viewed low in the southwest after sunset, starting the month in Libra with a magnitude of -3.9. On the 17th, it passes into Scorpius and then, on the 25th, into Ophiuchus. As it does so it will rise a little higher in the sky. But, despite its brightness, binoculars might well be needed to spot it, but please do not use them until after the Sun has set. During the month, its angular size increases from 12 to 14 arc seconds whilst the illuminated percentage of its disk falls from 86 percent to 78 percent. These two factors compensate each other so it brightness stays virtually constant. On the 5th, Venus passes just below the wide double star Alpha Librae whilst on the 20th it passes close to Delta Scorpii which forms part of the scorpion's head. Southern Hemisphere
Claire Bretherton from the Space Place Carter Observatory in New Zealand speaks about the Southern hemisphere night sky during October 2016.
Kia ora, and welcome to the October Jodcast from Carter Observatory in Wellington, New Zealand.
October is a good time to look out for the zodiacal light, seen as a triangular glow in the west after sunset in a clear, dark sky. It is caused by light reflecting off dust along the plane of our solar system. This plane is marked by the ecliptic, the apparent path of the Sun across the sky, which runs through the constellations of the zodiac. At this time of year the ecliptic makes a steep angle with the horizon, making the zodiacal light easier to observe.
As our nights are getting lighter and our days warmer our winter zodiac constellation of Scorpius/ te Matau a Maui drops down towards the horizon, taking cream-coloured Saturn with it. Saturn sits to the right of orange Antares, and with its 29.5 year orbit around the Sun, moves very little against the background sky. The pair set shortly before 11pm by the end of the month.
In sharp contrast, Venus, with its 225 day orbit, moves quickly eastwards against the background stars, appearing higher and higher in the western evening sky. By the end of the month it passes between Saturn and Antares, setting over 3 hours after the Sun.
Red Mars is higher still and continues to hold its position well this month, moving through the constellation ofSagittarius and setting after around 2 am. As we move away from Mars on our inner orbit, it is slowly slipping down the sky, and gradually becoming fainter, but it will remain in our evening skies well into the New Year.
If you have a good pair of binoculars or a small telescope, you might want to look for another planet this month. Uranus, the second most distant planet in the Solar System, reaches opposition on Saturday 15th. This is when Uranus lies on the opposite side of Earth to the Sun, reaching its highest point in our skies at around midnight. It is also around this time that Earth and Uranus are at their closest, although this won't make too muchdifference to the planet's brightness from our point of view.
Uranus will be above the horizon for much of the night, shining at magnitude 5.7 in the constellation of Pisces the fishes. On a very dark, clear night it may just be possible to glimpse Uranus with the naked eye, but a full Moon close to the time of opposition will make this impossible at that time. Better to look at either the start or end of the month, closer to the new moon. With binoculars, however, Uranus should be relatively easy to spot, as long as you know where to look, although it will appear as just a star like point of light without the use of a telescope.
A little to the north of Pisces is the constellation of Pegasus, the winged horse, which appears to leap across the northern horizon in our evening sky. Pegasus is easy to spot by the Great Square of stars that makes up his body.
The brightest star in the constellation is the reddish star Epsilon Pegasi, marking the horse's muzzle. This star is commonly known as Enif, deriving from the Arabic word for nose. Epsilon Pegasi is an orange supergiant, around 12 times the mass of the Sun , and with a radius some 185 times larger.
Nearby (and visible in the same binocular field of view) is the globular cluster M15, one of the oldest and best know star clusters in the sky, with an estimated age of around 12 billion years. The cluster is located around 34,000 light years away and measures 175 light years across. M15 is probably the most densely packed globular cluster in our galaxy, with half of its mass concentrated within 10 light years of the centre. It has been suggested that this massive concentration of stars may be caused by a rare type of supermassive Black Hole in the cluster's core.
With binoculars M15 will appear as a fuzzy star, whilst a medium sized or larger telescope will reveal individual stars, particularly towards the outer regions, appearing as chains and streams radiating out from the core.
M15 also contains the planetary nebula Pease 1, the first to be found within a globular cluster. At magnitude 15.5, this is a faint object, and a telescope with an aperture of at least 300mm would be needed to observe it.
The star at the bottom right of the Great Square of Pegasus is in fact Alpha Andromodae, or Alpheratz, the brightest star in the constellation of Andromeda. Located some 97 light years from Earth it is a spectroscopic binary star whose two components orbit each other in just 100 days.
Alpheratz is a great starting point to star hop to the great galaxy in Andromeda, or M31. The nearest large spiral galaxy to our own, M31 makes a rare appearance in our southern hemisphere skies at this time of year, but you'll need a good, dark sky and a clear view of the northern horizon to spot it. The further north you go, the better your chances of finding it.
From Alpheratz look for two chains of stars extending out to the east. Hop along the uppermost, and brightest, of these chains past Delta Andromedae to Mirach (Beta Andromedae), then turn sharp right and head down to Mu Andromedae before jumping on the same distance again to find the galaxy.
The Andromeda galaxy covers an area around 6 times the diameter of the full moon, but only the brighter central region is easily visible to the naked eye, or with binoculars or a small telescope.
At 2.5 million light years away, and magnitude 3.4, it is the most distant object easily visible with the naked eye. Andromeda is thought to contain around one trillion stars, well over twice the number estimated in our own Milky Way. Some recent studies, however, have suggested that the Milky Way may contain more dark matter than Andromeda, giving the two galaxies a similar mass.
M31 is approaching the Milky Way at 110 km/s and is expected to collide and merge with our Galaxy in around 4 billionyears.
A little higher and towards the east, the Triangulum galaxy or M33 is better placed in our skies. At around 3 million light years from Earth and shining at magnitude 5.7 it is just at the limit of naked eye visibility under excellent conditions, making it one of the most distant objects able to be glimpsed unaided. With the mass of 10s of billions of Suns, M33 is the third largest member of the local group. Like the Andromeda galaxy, it is also approaching us, at around 100,000 kilometres per hour.
To find M33, head back from Andromeda towards Mirach and then continue a similar distance to the other side. Whilst M33 with the naked eye is a challenge, it is easily observable in a pair of binoculars.
The most striking feature of the Triangulum Galaxy is a massive region of star formation, known as NGC604, which can be seen with a small telescope. NGC604 is 100 times larger than the Orion Nebula and contains over 200 hot, massive blue stars formed just 3 million years ago. In fact, if it were at the same distance as the Orion Nebula, only the Moon would be brighter in the night time sky.
Of course there are 2 galaxies that are always visible in our night sky, the Large and Small Magellanic clouds, which are circumpolar here in New Zealand. To find the Magellanic Clouds, first look for the bright star Canopus, twinkling colourfully, low in the southeast. The Magellanic clouds appear as two small smudges of light above it, they are irregular dwarf galaxies that neighbour our own. Whilst these galaxies are much smaller than the Milky Way, they still contain hundreds of millions of stars.
The Large Magellanic Cloud, or LMC, is the lower of the two and is located 160,000 light years away. Through binoculars or a small telescope you may be able to spot a number of young star clusters visible as small patches of light. The LMC also contains a massive star formation region, one of the largest and brightest known, called the Tarantula nebula or 30 Doradus. Spanning around 600 light years across, and covering 13 arcminutes in the sky,the Tarantula nebula contains over 800,000 stars and protostars and is the most active starburst region identified within our local group of galaxies. If it were placed at the same distance as the Orion Nebula it would be so bright that it would cast a shadow here on Earth.
The star formation activity within the Tarantula nebula began a few tens of millions of years ago, and some of the largest and brightest stars born within this region have already reached the ends of their short lives. In February 1987 supernova SN1987A was discovered in the outskirts of the Tarantula nebula by astronomers at Las Campanas Observatory in Chile, and independently by prolific amateur astronomer Albert Jones here in New Zealand. This supernova was the closest since the invention of the telescope just over 400 years ago and provided a unique opportunity for astronomers to study such an event in unprecedented detail. Reaching a peak magnitude of around 3, SN1987A was easily bright enough to spot with the naked eye.
Smaller and more distant, at around 200,000 light years, is the Small Magellanic Cloud, or SMC. To the top-right of this galaxy you may spot a faint fuzzy 'star'. This object is not actually associated with the SMC but is a beautiful globular cluster called 47 Tucanae, or NGC 104, and is actually located just a tenth of the distance away on the outskirts of our own galaxy. At magnitude 4.9 it is the second brightest globular cluster in the sky, after Omega Centauri, and can be easily seen with the naked eye. With a binoculars or a small telescope it is a wonderful sight, revealing a densely packed central core, whilst a larger telescope will start to resolve some of its millions of ancient stars.
Wishing you clear skies and happy galaxy hunting from the team hear at Space Place at Carter Observatory
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for September 2016
5 syys 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during September 2016.
The Stars
To the south and moving westward as night progresses you may see the Summer Triangle: the bright stars Deneb (in Cygnus), Vega (in Lyra) and below them Altair (in Aquila). Towards the south later in the evening you may spot the great square of Pegasus - adjacent to Andromeda and M31, the Andromeda Nebula. To the north lies "w" shaped Cassiopeia and Perseus. Between the two, close to the Milky Way, try to spot the Perseus Double Cluster with a goods pair of binoculars. You might also spot M33 may also be visible on a transparent night with a good pair of binoculars.
The PlanetsJupiter reached superior conjunction on August 26th, and now rises shortly before the sun. It will be best seen at month's end, 18 degrees above the northeast horizon at sunrise. With a disk increasing to 31 arcsecond disk, you should be able to see its equitorial bands and 4 Galilean moons.Saturn can be seen after sunset low in the southwest. It lies in eastern Libra, moving slowly away from the wide double star Alpha Librae as it shines with a magnitude of +0.6. One hour after sunset at the start of the month it will lie just 10 degrees above the horizon with a 16.4 arc second disk. By month's end it will only be a few degrees elevation at this time so early this month is really our last chance to observe it for a month or so as it passes behind the Sun. The ring system, now opened out to 24.3 degrees to the line of sight, should still be visible along with Titan, its largest satellite.Mercury can be seen just above the western horizon for the first few days of the month reaching greatest elongation from the Sun on the 4th of September shining at magnitude +0.1. It will be lost in the twilight by mid-month before it passes in front of the Sun (Inferior Conjunction) on the 30th.Mars is a pre-dawn object, and lies in Leo not far from Regulus, Alpha Leonis. On the 25th the salmon-pink planet will lie just 47 arc minutes from the blue star making a very nice colour contrast. Shining at magnitude +1.8 its disk is just 3.8 arc seconds across so no details will be seen of its surface. Seen best towards the end of the month, it will then rise around 3 hours before the Sun.Venus, rises in the east-northeast in the pre-dawn sky an hour and a half before the Sun at the start of September but this increases to four hour by month's end as Venus moves further away in angle from the Sun. Shining at a magnitude -4.8 during the third week of the month month it will show a thin crescent, 9% illuminated, 52 arc second disk as the month begins.The Moon
On September 4th and 21st you may spot The Alpine Valley, a cleft across the Appenine mountain chain. It is about 7 miles wide and 79 miles long and a thin rill runs along its length which is quite challenging to observe.
HighlightsNeptune came into opposition on the 29th of August, so will be seen well this month. Its magnitude is +7.9 so Neptune is easily spotted in binoculars lying in the constellation Aquarius as shown on the chart. It rises to an elevation of ~27 degrees when due south. Given a telescope of 8 inches or greater aperture and a dark transparent night it should even be possible to spot its moon Triton. Look east before dawn on 5th September: the magnitude +0.9 star Aldebaran will be occulted by the bright limb of the Moon as it passes in front of the Hyades cluster at around 05:30 BST. Given a mount tracking Aldebaran with a telescope, you may see it reappear from behind the unlit lunar disk at 07:10 in the bright daylight sky. Be warned: the times will vary by a few minutes depending on where you live in the UK so be watching Aldebaran for perhaps 10 minutes before the two stated times.All clear before dawn on 10th September given a good low unobstructed horizon towards the northeast you may spot an 8% lit, thin crescent Moon just 2 degrees to the upper left of Venus shining at magnitude -4.6.Looking southwest one hour after sunset on 18th September (20:45 BST), Saturn will be seen 4.5 degrees to the lower left of a waxing crescent Moon.About one hour before dawn on the morning of the 25th, Mars will be seen less than one degree just to the left of Regulus in Leo. Shining brightly up to their right will lie Venus, dominating the morning sky whilst lying well below Mars will be seen Jupiter - a very nice planetary grouping.Before dawn on 28th September, from 01:12 BST until 06:22 BST we will witness a total eclipse of a Harvest Supermoon! It will display the largest apparent angular diameter of the year (33.5 arc minutes) and the eclipse lasts for three hours and twenty minutes with totality starting at 03:11 BST and ending at 04:23. At the mid point of the eclipse at 03:47 BST the Moon will then lie at an elevation of 27 degrees above the southwest horizon. As the Moon leaves the umbral shadow 05:27 BST it will lie some 15 degrees above the horizon in the dawn sky.Southern Hemisphere
Claire Bretherton from the Space Place at Carter Observatory in New Zealand speaks about the southern hemisphere night sky during September 2016.
Kia Ora and welcome to the September Jodcast from Space Place at Carter Observatory, here in Wellington , New Zealand.
It's hard to believe that it's now a year since the birth of my daughter, Seren (whose name means star in Welsh, by the way) so after taking some time out to spend with her I'm back to pick up the reigns of the southern night sky jodcast. Huge thanks to Haritina for doing such an amazing job in my absence.
September marks the start of spring here in the southern hemisphere, and as we head towards the equinox on the 23 rd , our days begin to lengthen. Sunset and sunrise times change rapidly at this time of the year, with the Sun dipping below the horizon an hour and a half later at the end of the month than at the beginning. By the end of September the Sun won't be setting until nearly half past 7. Whilst we're looking forward to some better weather, this will also mean fewer hours of darkness to get out and observe our Southern skies.
All five naked eye planets continue their planetary dance this month. Jupiter, Mercury and Venus begin the month close together above the Western horizon after dark. Venus is the brightest and the highest of the three, easy to spot, even in the twilight sky. Jupiter, with its golden glow is below with fainter Mercury to the left. Mercury slips quickly into the twilight sky, with Jupiter following by mid-month. After passing between us and the Sun, Mercury will make a morning appearance during late September, but won't be rising until twilight is well underway, making it very difficult to spot.
Venus moves quickly up away from the other two, passing up to the right of 0.9 Magnitude Spica around the 19 th of the month. By the end of the month it will be setting over 2 and a half hours after the Sun.
Mars and Saturn still form a triangle with Antares, high in the northern sky after dark. Saturn is almost directly below Antares, and the two remain close together throughout the month gradually dropping lower in our evening skies and setting by around midnight at the end of September. Mars, the brightest of the three, begins the month just to the right of Saturn and Antares, but holds its position in the sky as it moves eastwards against the background stars, drifting up and to the right away from Saturn as the month wears on.
The bright stars Canopus and Vega mark north-south after dark this month. Canopus is the second brightest star in the night time sky, and the brightest in the southern constellation of Carina, the keel. Carina was once part of the great ship Argo Navis, which sails across the southern skies. In 1752, the French astronomer Nicolas Louis de Lacaille split Argo Navis into three smaller constellations of more manageable size: Carina (the keel), Puppis (the poop deck, or stern), and Vela (the sails).
To Maori Canopus is known as Atutahi or Autahi, meaning "stand alone" because of its isolated position outside the band of the Milky Way. Canopus represents the ariki, or high chief of the heavens, and is circumpolar here in New Zealand, always visible in our night time skies.
Vega, in the constellation of Lyra, is the fifth brightest star in the sky, and at just 25 light years away, one of the brightest in our local neighbourhood. It is also one of the best studied, and was the first star outside our Sun to be photographed in 1850. Vega is also extensively used by astronomers for photometric calibration. It is used as a zero point to define the UBVRI photometric system first introduced in the 1950s, and extended in the 1970s, to classify stars according to their colours.
Along with the nearby bright stars of Deneb, in Cygnus the swan, and Altair, in Aquila the eagle, Vega forms part of the "winter triangle" as seen here in the southern hemisphere. Altair is easy to spot, lying along the band of the Milky Way, midway up the northern sky after dark. Deneb is harder to see, just skirting along the horizon from northern parts of the country.
Between Vega and Altair is Albireo, or Beta Cygni, the beak star, marking the head of the swan. Although it appears as a single star to the naked eye, Albireo is in fact a double star and a lovely sight in a small telescope because of the easily seen contrast in colour between blue and gold components. The two stars are 35 arcseconds apart, meaning they are separated by 60 times the diameter of our Solar System, and may take 100,000 years to orbit each other.
The brighter magnitude 3 yellow star has also been found to be a binary star in its own right, but a much larger telescope and excellent observing conditions, or complex image processing, would be needed to resolve it.
Albireo is best viewed using low magnification, as the colours stand our more clearly when the stars appear close together. You might also try de-focussing your telescope a little to spread out the stars' light, making the colours easier to see.
A similar distance to the other side of Altair is Alpha Capricorni. Whilst it has the alpha designation, it is actually the 3rd brightest star in the zodiac constellation of Capricorn, the goat, and is commonly known as Al Giedi, meaning the kid. Alpha Cap is another double star, but this time the effect is purely coincidence.
Although these stars appear close together, their proximity is just a line of site effect, with the two components positioned at 109 and 690 light years away. Alpha-2, or Secunda Giedi is the closer and brighter of the two, a giant star with a luminosity around 40 times that of the Sun, and an apparent magnitude of 3.58. Alpha-1 or Prima Giedi is a supergiant over 5 times more distant, but at 5 times the mass and over 1000 times the luminosity of the Sun, it is only slightly fainter in our skies, at magnitude 4.3. Both are evolved G class yellow stars, at a similar temperature to our Sun, and Alpha Giediis a multiple star in its own right, with at least 3 faint companions nearby.
Prima and Secunda are located 6.6 arcminutes apart, around one fifth the diameter of the full moon, and can be separated fairly easily even with the naked eye.
As Haritina mentioned last month, the Milky Way is spectacular in our evening skies at this time of year, passing from Vega and Altair towards the north, through Sagittarius and Scorpius overhead, and down to the southern horizon, just to the west of Canopus. Midway up the southern sky you'll find Crux, the Southern Cross, with the pointers Alpha and Beta Centauri above.
Alpha Cen is another multiple star system, and at a distance of 4.37 light years, is the closest star system to our Sun. The two main components Alpha Cen A and B are both similar in mass and luminosity to the Sun and are close enough that they would fit within the orbit of Pluto. They are too close together to be resolved with the naked eye, but a pair of binoculars or small telescope will easily separate them.
The third component, Alpha Cen C, is a small, faint red Dwarf star, also known as Proxima Centauri, which can be glimpsed even in a small telescope. Lying 0.2 parsecs, or 15,000 AU from the AB pair, that's around 500 times the orbit of Neptune, Proxima Centauri's current distance of around 4.25 light years makes it the closest star to our Sun.
On 24 August, a team of astronomers led by Guillem Anglada-Escude, announced that they have discovered a potentially Earth-like planet orbiting around Proxima Centauri. The planet was identified using radial velocity measurements of its parent star. As the planet orbits it causes the star to wobble, and this wobble can be detected by measuring the Doppler shift in the stars spectrum.
Named Proxima b, the newly discovered planet takes just 11.2 days to orbit its star, putting it at 1/20 th of the distance from the Earth to the Sun, but, because Proxima is a much smaller, fainter star, the energy it receives is around 2/3 s the energy that reaches Earth, so Proxima b lies firmly in the habitable zone, the region of space where any water on the planet could be liquid. With a minimum mass of 1.3 times the Earth, this opens up an exciting possibility that not only have we found a planet around our nearest star, but that this planet may be Earth-like, and potentially, able to support life.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for August 2016
1 elo 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during August 2016.
Highlights of the month
August - Find the globular cluster in Hercules and spot the "Double-double" in Lyra

There are two very nice objects to spot with binoculars high in the sky after dark this month. Two thirds of the way up the right hand side of the 4 stars that make up the "keystone" in the constellation Hercules is M13, the best globular cluster visible in the northern sky.
Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name.

August - A good month to observe Neptune with a small telescope.

Neptune comes into opposition - when it is nearest the Earth - on the 2nd of September, so will be well placed both this month and next. Its magnitude is +7.9, so Neptune, with a disk just 3.7 arcseconds across, is easily spotted in binoculars lying in the constellation Aquarius, as shown on the chart. It rises to an elevation of ~27 degrees when due south. Given a telescope of 8 inches or greater aperture and a dark tranparent night it should even be possible to spot its moon Triton.

August 1st after sunset: Jupiter, Mercury, Regulus and Venus form a line in the Western Sky.

Given a clear sky and a very low western horizon you may be able to spot a line of Jupiter, Mercury and Venus along with Regulus in Leo. Binoculars may well be needed, but please do not use them until the Sun has set.

August 5th after sunset: Jupiter and a thin waxing crescent Moon

As Jupiter slowly sinks into the Sun's glare, given clear skies and a low western horizon it should be possible to spot Jupiter up and to the left of a thin waxing crescent Moon.

August 23rd - after sunset: Saturn and Mars lie above Antares in Scorpius

Looking South-Southwest after sunset and given a low horizon in this direction you should be able to spot Saturn (+0.4) lying above Mars (-0.3) (both in Ophiuchus) close to Antares in Scorpius.

August 27th - after sunset: Venus and Jupiter less than half a degree apart.

Looking west after sunset and given a very low horizon in this direction, binoculars may help you spot Jupiter and Venus less than half a degree apart. But please do not use binocluars until after the Sun has set.

August 11th and 25th: The Straight Wall

The Straight Wall is best observed either 1 or 2 days after First Quarter (evening of the 11th August best) or a day or so before Third Quarter (evening of the 25th August best). To honest, it is not really a wall but a gentle scarp - as Sir Patrick Moore has said, "Neither is it a wall nor is it straight."

Observe the International Space Station
Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK and across the world.
Find details of sighting possibilities from your location from the location index. See where the space station is now using the tracking page.

The Planets Jupiter
Jupiter can be seen low above the western horizon after sunset but throughout the month is sinking slowly into the Sun's glare. However as it does so, it makes some groupings with the crescent Moon, Mercury and Venus as highlighted above. It remains at magnitude -1.7 throughout August whilst its angular diameter reduces slightly from 32.1 to 30.9 arcseconds. Its low elevation will hinder our view of the giant planet but a small telescope should still show its equatorial bands and the Gallilean moons as they weave their way around it. Saturn
Saturn has its rings as nearly open as they can be and so still makes a great sight through a small telescope even though its elevation never gets above ~20 degrees. It dims slightly from magnitude +0.3 to +0.5 during August as its angular size falls slightly from 17.5 to 16.7 arcseconds. Saturn transits at sunset and so can be seen low in the south-western sky during the evening. With a small telescope one should also be able to spot its largest moon, Titan. As described in the highlights, towards the end of the month Saturn, Mars and Antares make a close grouping. Mercury
Mercury reaches greatest elongation from the Sun on August 16th but, sadly, never gets that high above the horizon in the western sky. It magnitude falls throughout August from -0.2 to +1.1 whilst its angular size increases from 6 to 9.5 arcseconds. Mars
As August begins, Mars, shining at magnitude -0.8, transits around sunset and so will be seen in the south-western sky during the evening as it moves first from Libra into Scorpius and then towards the end of the month into Ophiuchus. Its magnitude drops from -0.8 to -0.3 during the month as its angular size falls from 13 to 10.5 arcseconds. Sadly, its low elevation will hinder our view but it may still be possible to see some features on the surface with a small telescope if the atmospheric 'seeing' is good. Venus
Venus can be seen very low in the western sky after sunset so, despite its brilliant magnitude of -3.8, will still be hard to spot. Its angular diameter increases from 10.1 to 10.9 arcseconds during the month. On August 1st, it sets about 45 minutes after the Sun lying very close to the star Regulus in Leo. An interesting, but difficult observation due to its very low elevation on the 27th will find it less than half a degree away from Jupiter as both fall into the Sun's glare.
Haritina Mogosanu from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during August 2016.
Haritina Mogosanu from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during August 2016.
In the Southern Hemisphere, winter is the time when the galactic center goes right all the up at Zenith. All you have to do from here in Wellington, New Zealand is to lift up your gaze and it will be right there. From there, if there is a really dark night, you can see the Milky Way Kiwi, which I spoke about in last month's jodcast. It is a dark patch at the center of our galaxy, the Milky Way, that looks just like a Kiwi bird, one of the native birds of New Zealand, and a national icon for us. It is truly remarkable how the kiwibird in the sky resembles to the one on the earth. But since you need a really dark sky, I would suggest that the best thing you can do to try spot the Milky Way Kiwi is to start looking for it in long exposed pictures of the night sky. The only place in New Zealand where I could see it with the naked eye was at Lake Tekapo's Earth and Sky. Whereas the Milky Way Kiwi is in the Scorpius Sagittarius region, holding the center of the galaxy on its head like a crown, the other famous dark patch is the Coalsack, near the Southern Cross. The coalsack is also known as the flounder, which is the Maori name for it. In deed, again if you find a truly dark sky, you will see the resemblance. However, talking about naming objects in the sky, the coalsack is also very appropriate as the dark patch, made of interstellar dust matter holds inside it a jewelbox, or the Kappa Crucis Cluster, NGC 4755. This is an open cluster in the constellation Crux, originally discovered byNicolas Louis de Lacaille during 1751-1752 and named the Jewell box by Sir John Herschel. He described its telescopic appearance as "...a superb piece of fancy jewellery". Jewel box is easily visible to the naked eye as a hazy star about 1.0 degrees southeast of the first-magnitude star Beta Crucis.
In August, after sunset, the Southern Cross, Crux, and the two pointers, Alpha and Beta Centauri, are slowly starting their descent on the south celestial carousel, our special part of the sky that is not visible from Northern latitudes above 30 degrees. They are midway down the southwest sky. The pointers point down and rightward to Crux the Southern Cross. Alpha Centauri is the third brightest star and the closest naked eye star-neighbour, 4.3 light years* away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away and thousands of times brighter than the sun.
There is a part of the sky here in Wellington that seems to rotate around the South Celestial Pole, the extension of the South Pole in the sky, located here at 41 degrees above the horizon. This coincides with Wellington's latitude, 41 degrees South. You can almost make the South Celestial Circle from the two pointers, Alpha and Beta Centauri, the Southern Cross, the Diamond Cross, the False Cross, then lower down on the south-western horizon Canopus, the second brightest star in the sky, and Achernar, which is easily found if you exend a line from the southern cross all the way to the southeastern horizon. The South Celestial Circle makes an entire rotation in 23 hours, 56 minutes and just about 4 seconds, which is a sidereal day. This is a "time scale that is based on Earth's rate of rotation measured relative to the fixed stars" rather than the Sun. The south celestial circle is home to the Large and Small Clouds of Magellan LMC and SMC that look like two misty patches of light low in the south, easily seen by eye on a dark moonless night. They are galaxies like our Milky Way but much smaller. The LMC is about 160000 light years away; the SMC about 200000 light years away. My two favourite objects inside the south celestial circle are the globular cluster 47 Tucanae (rival of Omega Centauri) and the Tarantula Nebula, a spectacular cloud which is one of the most active starburst region known in the Local Group of galaxies. To give you an comparison, the Tarantula Nebula is about 160 000 light years away from us. Its luminosity is so great that if it were as close to Earth as the Orion Nebula, the Tarantula Nebula would cast shadows. The South Celestial Circle never ceases to amaze me and I watch it as it rotates with the seasons and througout the night when I can. For me, the southern part of the sky, is the best and I am extremely happy that i had the chance to see it, let alone now teach about it.
Back to the ecliptic, which is visible from everywhere where people can see the Sun and the Moon, as it is defined as the path of Sun but also as the plane of our Solar System, all five naked-eye planets are visible in the early evening sky. Mercury, Venus and Jupiter are low in the west and shuffle around through the month. Mars and Saturn are north of overhead near Antares.
Venus, the brilliant silver 'evening star', sets in the west an hour after the sun at the beginning of the month, extending to nearly two hours by the end. Jupiter, higher in the west and golden-coloured, sets steadily earlier through the month: at 9 pm at the start of August and before 8 pm at the end. Mercury makes its best evening sky appearance of the year. It is roughly midway between Jupiter and Venus at the beginning of the month. Around the 20th Mercury will be left of Jupiter but much fainter. It begins to sink back into the twilight at the end of the month. On August 27-28, Jupiter and Venus will be close together, easily included in the same view in a telescope. At the beginning of August, Mars, Saturn and Antares make an isosceles triangle north of the zenith. Mars is the brightest of the three and the same colour as Antares. Saturn is cream-coloured. Saturn stays put against the background stars. Mars moves steadily eastward. On the 25th Mars will be two degrees, four full-moon diameters, from Antares making a striking pairing of orange stars.
Bright stars are widely scattered. Vega on the north skyline is balanced by Canopus low in the south. Orange Arcturus is in the northwest. The Southern Cross, Crux, and the Pointers are midway down the southwest sky. The Milky Way spans the sky from northeast to southwest. Canopus, the second brightest star, is near the south skyline at dusk. It swings upward into the southeast sky through the morning hours. On the opposite horizon is Vega, one of the brightest northern stars. It is due north in mid-evening and sets around midnight. Arcturus, Hokulea, the Zenith star of Hawaii is in the northwest at dusk. The fourth brightest star, Arcturus is currently the brightest in the northern hemisphere. It is 120 times the sun's brightness and 37 light years away. When low in the sky Arcturus twinkles red and green as the air splits up its orange light. It sets in the northwest around 10 pm. Antares marks the heart of the Scorpion. The Scorpion's tail hooks around the zenith like a back-to-front question mark. Antares and the tail make the 'fish-hook of Maui' in Maori star lore. The fishing hook drags at this time of hte year the Milky Way down from the heavens. Antares is a red giant star 600 light years away and 19000 times brighter than the sun. Below or right of the Scorpion's tail is 'the teapot' made by the brightest stars of Sagittarius. It is upside down in our southern hemisphere view.
The Milky Way is brightest and broadest overhead in Scorpius and Sagittarius. In a dark sky, it can be traced down past the Pointers and Crux into the southwest. To the northeast it passes Altair, meeting the skyline right of Vega. The Milky Way is our edgewise view of the galaxy. The thick hub of the galaxy is in Sagittarius 30000 light years away. The actual centre is hidden by dust clouds in space. The nearer dust clouds appear as gaps and slots in the Milky Way. Binoculars show many clusters of stars and some glowing gas clouds in the Milky Way.
According to Karen W. Pierce who made an excellent list of binocular objects that you can find on the site astrogeek.com, in Ophiuchus, you can find M9, M10, M12, M14, M19, and M6, which provide examples of different concentrations of stars. Also visible is IC 4665, a big but often overlooked open cluster located near Beta Ophiuchi. On a dark night, it is visible to the naked eye as a hazy splotch nearly I degree across.
Sagittarius contains more Messier objects than any other constellation. The best way to identify them is to take them one by one. The main stars of Sagittarius form the famous "Teapot" asterism, which here in Wellington looks upside down. It is said that for the Norhtenlings, the brightest part of the Milky Way seems to emerge from the Teapot's spout like a puff of steam. In Sagittarius, M22, the Great Sagittarius star cluster is a very large globular — the best of the constellation's many globulars. At magnitude 5.1 it is an easy binocular object. M23 is another one of the many clusters in Sagittarius. M23 presents over 100 stars in an area about the size of the Moon. The Lagoon Nebula, M8, is visible with the naked eye in dark nights just north of the richest part of the Sagittarius Milky Way. The Trifid Nebula, M20, is found only 1 1/2 degrees northwest of the Lagoon Nebula. Ideal conditions and sharp eyes might detect M21, which is located just 1/2 degree northeast of M20, although it is rather faint by binocular standards. Omega Nebula, also called M17 or the Swan, the Horseshoe or the Checkmark, can be seen clearly in binoculars. In Scorpius, Antares, or Rehua in Maori, is the Heart of the Scorpion. A red giant star about 10000 times more luminous than the Sun is a good binocular object. M4 is a globular cluster that in binculars looks like a fuzzy patch. M6, the Butterfly Cluster, is a large open cluster of about 50 stars resembles a butterfly. M7 is a large, bright open cluster that lies southeast of M6 but needs to be seen through binoculars to be fully appreciated. NGC 6231 is a bright open cluster that lies in a rich region of the Milky Way. It is best surveyed in binoculars or at very low power in a telescope. In this same area of the scorpion's tail are several other binocular-visible objects but I will let you discover these, as that region of the sky comes about and remember that you don't need fancy telescopes to enjoy the night sky but a pair of good bionculars a good sky atlas and lots of hot chocolate. It's winter time here in the Souther Hemisphere and the nights are crisp but cold. Keep warm and look up.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for July 2016
9 heinä 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during July 2016.
Highlights of the month
July - Still worth observing Saturn
Saturn reached opposition on the 3rd of June, so is now low (at an elevation of ~ 20 degrees) in the west-southwest as darkness falls lying just over 6 degrees above the orange-red star Antares in Scorpius.   Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good "seeing" (when the atmosphere is calm) will show Saturn and its beautiful ring system in its full glory.

As Saturn rotates quickly with a day of just 10 and a half hours, its equator bulges slightly and so it appears a little "squashed". Like Jupiter, it does show belts but their colours are muted in comparison.

July - Find the globular cluster in Hercules and spot the "Double-double" in Lyra
There are two very nice objects to spot with binoculars high in the south-western sky well after dark this month. Two thirds of the way up the right hand side of the 4 stars that make up the "keystone" in the constellation Hercules is M13, the best globular cluster visible in the northern sky.

Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name!
Early July around midnight: look north to spot Noctilucent clouds.
Noctilucent clouds, also known as polar mesospheric clouds, are most commonly seen in the deep twilight towards the north from our latitude. They are the highest clouds in the atmosphere at heights of around 80 km or 50 miles. Normally too faint to be seen, they are visible when illuminated by sunlight from below the northern horizon whilst the lower parts of the atmosphere are in shadow. They are not fully understood and are increasing in frequency, brightness and extent; some think that this might be due to climate change! So on a clear dark night as light is draining from the north western sky long after sunset take a look towards the north and you might just spot them!
July 1st, 1 hour after sunset: Saturn and Mars make a triangle with Antares
Around one hour after sunset on July 1st, given a clear sky and low southern horizon, you should be able to spot Saturn, above, and Mars, over to the right, or Antares in Scorpius.
July 8th, 1 hour after sunset: A Waning Crescent Moon near Jupiter
Around one hour after sunset on July 8th, given a clear sky and low western horizon, you should be able to spot Jupiter, above and to the left of a thin crescent Moon.
July 16th after sunset: Venus and Mercury half a degree apart
July 29th before dawn: A thin waning crescent Moon close to Aldebaran and the Hyades Cluster.
July 30th after sunset: Mercury very close to Regulus in Leo.
July 13th and 26th: Two Great Lunar Craters
Two great Lunar Craters: Tycho and Copernicus
These are great nights to observe two of the greatest craters on the Moon, Tycho and Copernicus, as the terminator is nearby. Tycho is towards the bottom of Moon in a densely cratered area called the Southern Lunar Highlands. It is a relatively young crater which is about 108 million years old. It is interesting in that it is thought to have been formed by the impact of one of the remnents of an asteroid that gave rise to the asteroid Baptistina. Another asteroid originating from the same breakup may well have caused the Chicxulub crater 65 million years ago. It has a diameter of 85 km and is nearly 5 km deep. At full Moon - seen in the image to the right - the rays of material that were ejected when it was formed can be see arcing across the surface. Copernicus is about 800 million years old and lies in the eastern Oceanus Procellarum beyond the end of the Apennine Mountains. It is 93 km wide and nearly 4 km deep and is a clasic "terraced" crater. Both can be seen with binoculars.
Observe the International Space Station
Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK. (Across the world too for foreign visitors to this web page.)

Note: I observed the ISS three times recently and was amazed as to how bright it has become.

Find details of sighting possibilities from your location from: Location Index

See where the space station is now: Current Position
The Planets Jupiter
Seen low in the western sky after sunset, Jupiter is shining at magnitude -1.9 at the start of the month and has an angular diameter of 34.3 arc seconds. By month's end, these have reduced slightly to -1.7 magnitudes and 32.1 arc seconds. One hour after sunset it will be about 30 degrees above the horizon. Jupiter passes half a degree below the 4th magnitude star, Sigma Leonis on July 12th and continues to move eastwards, moving towards the Leo-Virgo boarder. Due to the low elevation, the atmosphere will limit our view somewhat but up to four of the Gallilean moons will be visible as well as the dark equatorial bands. The Great Red Spot will be harder to spot unless the seeing and transparency of the atmosphere are good.

Saturn
Saturn, having been in opposition on June 3rd, lies some 6 degrees north of Antares (in Scorpius) in southern Ophiuchus. It continues its retrograde motion westwards across the sky throughout July, narrowing its gap between Mars (now moving eastwards) from 19 degrees to 11 degrees as the month progresses. At the same time the brightness drops a little, from magnitude +0.1 to magnitude +0.3 whilst its apparent diameter falls from 18.2 to 17.6 arc seconds. Though only at an elevation of 20 degrees when due south at around 11 pm as July begins (and 9pm at month's end) the beautiful ring system, now at an inclination of 26 degrees is still worth observing as is Saturn's brightest Moon, Titan.

Mercury
Mercury passes behind the Sun (Superior Conjunction) on July 6th, but may become visible in binoculars about mid month when it sets about 45 minutes after sunset as it lies just half a degree above Venus. During July's final week it will be seen to the upper left of Venus and moves closer to Regulus, in Leo, until the two close to just 22 arc minutes on the evening of July 30th.

Mars

Venus
Venus, having passed behind the Sun on June 6th becomes visible in mid month low in the west-northwest shining at magnitude -3.9 in Gemini. It passes to the lower left of Pollux on the 13th andpasse through the Beehive Cluster, M44,in Cancer on the 20th, ending the month 5 degrees to the west of Regulus in Leo.

Southern Hemisphere
Haritina Mogosanu from the Carter Observatory in New Zealand tells us about the southern hemisphere night sky during July 2016.
My name is Haritina Mogosanu and tonight I am your starryteller from the Southern Hemisphere. In this jodcast episode I will talk about flying, since it is something I have always loved the most, besides the stars. This podcast is for Stephen who also likes flying.
I always look up for planes and stars altogether, and I've always been happiest in the air. And many times I forget that whilst I am thinking that I am sitting still here on Earth yearning to be there in the skies, our planet is moving at an incredible speed.
Moving but in relation to what? This is a good question. Well, to start with a point of reference, Earth is hurtling at 30 km per second around the Sun. We could measure these orbits in birthdays. One rotation, one birthday. So it takes Earth a year to go around the Sun once. The Sun also revolves around the Milky Way at 250 km per second. So that means that by the time we blink twice we already covered the distance from Wellington to Rotorua. Since our galaxy is larger than that, it takes roughly 230,000,000 Earth years to go around the Milky Way once... So one galactic year ago the trilobites were swimming in Earth's oceans...
But that's not the fastest speed out there... According to Scientific American, the galaxies in our neighborhood are also rushing at about 1,000 kilometers per second towards a structure called the Great Attractor, a region of space roughly 150 million light-years (one light year is about nine and a half trillion kilometers) away from us.
In terms of starry wings, there are many creatures out there among the asterisms imagined by humans. I will start with my absolute favourite object, which was discovered only a quarter of a century ago, the Milky Way Kiwi.
July is the time when the centre of our galaxy, the Milky Way, is climbing all the way to the Zenith and from there, if there is a truly dark night, you can see the Milky Way Kiwi. Now you do need a very dark sky for that, and you need to know what you are looking for. Best you can see the Milky Way Kiwi in long exposed pictures of the night sky but I have seen it with the naked eye from Lake Tekapo Earth and Sky. Before I came to New Zealand, I had not known it existed, I've always thought that the dark patch I was looking at, if I was lucky enough to see it, was a dark horse. Suspended in the fabric of space, the center of our galaxy only rose about 30 degrees above the horizon, where I am from, near the 45 degrees North parallel. Besides, I did not even know what a kiwi bird was truly, let alone a celestial kiwi bird.
Another favourite of mine is Cygnus the Swan. It's my home zenith constellation back in the Northern Hemisphere where it is also known as the Northern Cross. Cygnus is juxtaposed on the Milky Way. Very low on the Northern horizon here, it's main star Deneb is barely grazing the earth looking as if it's a slow moving flame that brazes the land with the galaxy. It rises one hour after midnight, as seen from Wellington New Zealand. A tad higher than Deneb, my favourite star, double star, - well actually triple, Albireo, is resolved in telescopes as one aqua blue and one orange star. That's a sight worth seeing at least every night when Albireo is in the sky. Cygnus rises around midnight.
Aquila, the Eagle is another beautiful bird that flies in the Northern part of the sky, is low on the horizon rising, just after 8pm. Right at its tail, there is NGC 6751, a planetary nebula that looks just like an iris. Altair is the brightest star in Aquila and it's on the Milky Way.
Opposite Deneb and Altair, on the south western part of the evening sky, Sirius is setting whilst Canopus is descending from heavens. In between Sirius, and Canopus, is the constellation Columba. The cat and the dog are chasing the Dove, which is what Columba means. For deep sky observing, near Phaet, the alpha star, brightest star from Columba, there is a beautiful spiral galaxy, NGC1808.
Delicate and rich in optical double stars that we can seen with the naked eye, Grus the Crane is another bird-constellation laying now on the South Eastern Horizon. From Capricornus, that looks like a golf flag from here, hop two more blocks, passing another favourite star of mine, Fomalhaut, the loneliest star, in Piscis Austrinus and next stop south is Grus. I remember seeing Grus in a picture for the first time whilst Comet McNaught was here in New Zealand in 2006 and getting very excited about being able to recognise it by the multiple double stars in it.
Since we are at the southern side of the sky, to be fair, as much as I don't like them, Musca, the Fly also qualifies for a flying creature. Near the southern cross, Musca looks like a patrulater. A small one, peering inside the coalsack. At the end of its abdomen, NGC4833 is a rather nice globular cluster. Near Musca, Apus, the bird of paradise's name literally means "no feet" in Greek, as it was once wrongly believed that the birds of paradise lack feet. Apus is pointing straight at Pavo the peacock, that is flaunting with feathers all over the south celestial circle. Next to Pavo, is Toucana, near the Small Magellanic Cloud (NGC 292). Some spectacular deep sky objects near it are the famous NGC104 also known as 47 Tucanae, but also NGC362, another globular cluster, NGC346 Open Cluster, NGC 290, open cluster and NGC265 Open Cluster. Toucana is neighbouring Grus on one side and the Phoenix, on the other side. Since Herodotus, the Greek historian, the bird of Phoenix was associated with the Sun, a phoenix obtains new life by arising from the ashes of its predecessor and it can live for 1400 years at the time. Inside the constellation, NGC55 is an irregular galaxy and NGC 300 is a spiral galaxy. The main star in Phoenix, Ankaa is almost halfway through Achernar and Fomalhaut.
But a dark patch that looks just like a kiwibird, that is something that perhaps not too many people saw coming. Not too many people from New Zealand, I mean, because as i have discovered, being shown a kiwi bird, very few foreigners (I'm not counting the tourists here tho) can guess what that is.
So the Milky Way Kiwi does carry all the weight of our stars. Not surprising, given what its equivalent on Earth, the kiwibird did. There is a beautiful Maori legend telling how the kiwibird lost its wings.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for June 2016
10 kesä 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during June 2016.
Highlights of the month
June 1st - 8th: Mars at its best for 11 years.
Mars reaches opposition - that is when the Earth lies between the Sun and Mars and when it was be approximately due south at midnight (UT) or 1am (BST) - on the 22nd of May, so it will be visible for most of the hours of darkness. However, it was actually be closest to the Earth and so having its greatest angular size of 18.6 arc seconds some 8 days later on the 30th of May. The angular size at closest approach varies due to the ellipticity of the orbit of Mars (and to a far lesser extent to that of the Earth) and will reach 26 arc seconds during 25,695 AD. At closest approach in 2003, Mars reached an angular size of 25.1 arc seconds, its largest angular diameter for 60,000 years. In July 2018 it will reach 24.2 arcseconds across but for both this opposition and that in 2018, Mars will be very low in the ecliptic and hence at low elevation so that the atmosphere will limit our views of the red (actually salmon pink) planet. Happily, it will be higher in the sky at the opposition of 2020.

To find what should be visible at any time, one can use the Sky &Telescope application.
June - The best month to observe Saturn.
Saturn reaches opposition on the 3rd of June, so is now due south and highest in the sky around midnight (UT) or 1am (BST).
It lies in the southern part of Ophiuchus 7 degrees up and to the left of the orange star Antares in Scorpius.
Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good 'seeing' (when the atmosphere is calm) will show Saturn and its beautiful ring system in its full glory.
As Saturn rotates quickly with a day of just 10 and a half hours, its equator bulges slightly and so it appears a little 'squashed'. Like Jupiter, it does show belts but their colours are muted in comparison.
The thing that makes Saturn stand out is, of course, its ring system. The two outermost rings, A and B, are separated by a gap called Cassini's Division which should be visible in a telescope of 4 or more inches aperture if seeing conditions are good. Lying within the B ring, but far less bright and difficult to spot, is the C or Crepe Ring.
Due to the orientation of Saturn's rotation axis of 27 degrees with respect to the plane of the solar system, the orientation of the rings as seen by us changes as it orbits the Sun and twice each orbit they lie edge on to us and so can hardly be seen. This last happened in 2009 and they are now opening out, currently at an angle of 26 degrees to the line of sight. The rings will continue to open out until May 2017 and then narrow until March 2025 when they will appear edge-on again.
June - Find the globular cluster in Hercules and spot the "Double-double" in Lyra
There are two very nice objects to spot with binoculars in the eastern sky well after dark this month. Two thirds of the way up the right hand side of the 4 stars that make up the "keystone" in the constellation Hercules is M13, the best globular cluster visible in the northern sky. Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae often called the double-double. With binoculars a binary star is seen but, when observed with a telescope, each of these two stars is revealed to be a double star - hence the name!
June 3rd just before dawn: Mercury close to a very thin crescent Moon.
Some 30 or so minutes before dawn on the 3rd of June and given a low eastern horizon and clear skies it would be possible to spot Mercury, shining at magnitude +0.7 just 3 degrees to the left of a very thin crescent Moon.
Late June: A very good time to spot Noctilucent Clouds!
Noctilucent clouds, also known as polar mesospheric clouds, are most commonly seen in the deep twilight towards the north from our latitude. They are the highest clouds in the atmosphere at heights of around 80 km or 50 miles. Normally too faint to be seen, they are visible when illuminated by sunlight from below the northern horizon whilst the lower parts of the atmosphere are in shadow. They are not fully understood and are increasing in frequency, brightness and extent; some think that this might be due to climate change! So on a clear dark night as light is draining from the north western sky long after sunset take a look towards the north and you might just spot them!
Night of June 15 to 16th when fully dark: The Lyrid Meteor Shower
The June Lyrid meteor shower reaches its peak on the night of the the 15th/16th with a rate at the zenith of ~8 meteors per hour. This is not many and, as full Moon on the 20th is approaching, it may be hard to spot one. The radiant is very close to the star Vega. Many more meteors were seen from the shower in the late 1960's but the peak hourly rate has dropped off markedly since then. If clear, it may still be worth aiming to see if you can spot one.
June 14th and 15th: The Alpine Valley
These are two good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the limb (on the 14th) is the Apennine mountain chain that marks the edge of Mare Imbrium. Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image a thin rill runs along its length which is quite a challenge to observe. Over the next two nights the dark crater Plato and the young crater Copernicus will come into view. This is a very interesting region of the Moon!
Observe the International Space Station
Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK. (Across the world too for foreign visitors to this web page.)

Note: I observed the ISS three times recently and was amazed as to how bright it has become.

Find details of sighting possibilities from your location from: Location Index

See where the space station is now: Current Position
The PlanetsJupiter
Jupiter is now past its best, but still stands out in the southwest and west at nightfall. Its brightness falls slightly from magnitude -2.1 to -1.9 whilst its angular size drops from 37 to 34 arc seconds. Jupiter is now in the lower part of Leo, slowly moving eastwards towards Virgo which it will enter in August. Our best views of the planet are now past for this apparition but, with a small telescope one may well be able to see the equatorial bands in the atmosphere and up to four of the Galilean moons as they weave their way around it.Saturn
Saturn reaches opposition - that is when it be approximately due south at midnight (UT) or 1 am (BST) - on June 3rd, and so will be visible in the southeast at nightfall and will not set until dawn the following morning. It is moving slowly in retrograde motion in the lower part of Ophiuchus but close to the the fan of three stars that makes up the head of Scorpius and about 7 degrees up and to the left of Antares. This is a good time to observe Saturn whose globe is ~18 arcseconds across and whose rings span some 41 arcseconds across. They make a beautiful sight as are tilted 26 degrees from the line of sight - almost as open as they can be. It is sad that Saturn is now in a low part of the ecliptic and will only reach an elevation of 20 degrees when due south. I was able recently able to view it through a 16" telescope from a latitude of +29 in the Sahara Desert and it was stunning - perhaps a trip to the southern hemisphere is called for!

See highlight above.Mercury
Mercury is a pre-dawn object for the first week or so of the month best seen about 30-45 minutes before sunrise. It starts the month at magnitude +0.8 with an angular size of 9 arcseconds. This increases to magnitude zero by the 11th - perhaps the best time to view - with the angular size having dropped to 7.3 arc seconds. It will then be only ~7 degrees above the horizon so still be difficult to spot and a good low horizon in the east will be needed..

See highlight above.Mars
Mars reaches opposition on May 22nd and came closest to the Earth for 11 years on the 30th. So June is a second excellent month to observe the salmon-pink planet. Mars starts the month at magnitude -2, drops to to -1.7 by the 16th and -1.4 by month's end. At the same time the angular size drops from 18.6 to 16.4 arc seconds. Mars moves in retrograde motion in Libra until the 30th when it resumes its eastwards path through the stars moving back towards Saturn.

See highlight above.Venus
Venus reaches superior conjunction (that is directly behind the Sun) on June 6th and so cannot be observed this month. Southern Hemisphere
Haritina Mogosanu from the Carter Observatory in New Zealand tells us about the southern hemisphere night sky during June 2016.
Clear skies from from the top of Mount Victoria, in Wellington and greetings from Space at Carter Observatory in Aotearoa New Zealand.
My name is Haritina Mogosanu and tonight I am your starryteller from the Southern Hemisphere.
Top of Mount Victoria here in Wellington New Zealand is where I always felt on top of the world. To the South, I can sense Antarctica's frozen breath. To the North, I see glimpses of my faraway home-beacons: Andromeda, Arcturus and Vega. They are like a safety net. Something familiar. East and West are obviously looking weird – the Sun moves from right to left in the sky in the Southern Hemisphere, leaning towards North. In the Northern Hemisphere the Sun still goes from east to west but moving from left to right leaning towards South. So as I said before in previous episodes of the Jodcast, the shadow in the afternoon here looks just like the shadow of the morning in the Northern Hemisphere.
Being in the city of Wellington makes me feel grateful for the courage to leave my safe shore back home to seek my diamonds in the sky. Wellington at night glows like a net of diamonds itself. And it's the best sky that probably any capital of the world has ever seen. As for the star lore that people brought here… well… it's the most spectacular by far!
Which brings me to the month of June when here in New Zealand we celebrate the Maori New Year, Matariki.
Matariki is a lunar celebration. As you do with the Polynesian cultures, not everyone does everything in the same way but some tribes celebrate the new year, te Tau Hou, by observing the heliacal rising of the Pleiades, M 45, or as the cluster is called at this time of the year by Maori, Matariki. Some tribes use the star called Puanga (or Rigel). But no matter what marker they use, they observe its heliacal rising (that is before the Sun) just after the first new Moon that occurs after the longest night. I feel compelled to mention the fact that they only call the cluster Matariki at this time of the year, in the morning. The same stars appear in the asterism of Te Waka O Tama Rereti, present on the November's night sky and also three months later when they make Te Tawhiti, the shining one. I spoke about these asterism in Jodcast episodes from previous months. But nobody calls them Matariki then. The small group of stars are just part of something bigger. This was quite a discovery for me because in the western skylore, asterisms have only one name no matter what time of the year it is. As I was going to discover later, not only Matariki - The Pleiades are part of shapeshifting stories in the sky but also most of Maori legends include constellations that are only seasonal.
Back to the new year, here in Aotearoa New Zealand, the beautiful cluster of MataAriki, the eye of the God, rises before the Sun to mark the new year just after the new Moon's occurrence. The cluster will start being visible towards the middle of the month, that is if you wake up very early in the morning, just before sunrise, and look east. However, the first new Moon of June is on the 5th, but the cluster will be too low on the horizon to see. Counting the fact that Wellington's landscape is quite hilly, and the fact that the Maori tohunga tatai arorangi (astronomers) had to see the cluster visually before they could declare the new year, that positions, realistically, the period of Matariki, just after the longest night of the year, the winter solstice, which is also occurring in June. The next new Moon after the 5th of June is on 4th of July. Technically, the period of the new year lasts for about a month from one new Moon to the other and for some tribes was the time in between the years, when everything would reset and people would visit the year that has passed and think ahead to the year that would follow. You can hear more about Matariki and Maori astronomy in this month's interview that I took with Toa Waaka, vice chair of the Society for Maori Astronomy, Research and Traditions.
In Wellington this year Space Place at Carter Observatory has organised two dawn ceremonies. The first is on Saturday the 18th of June and the second is on the 22nd of June. That is of course providing the weather stays clear. You can always check our website for more details. And also of course, this month we will be incorporating Maori astronomy in our talks. The dawn ceremony will be held on top of Mount Victoria, where we go every year and it will start from 5:30 AM. Feel free to come along - there will be hot chocolate!
Back to our evening sky, bright planets light up the sky along with the brightest stars once again. Golden Jupiter appears midway up the north sky soon after sunset. Orange Mars is due east. Jupiter and Mars are similar in brightness but you can tell them apart by colour and position. Cream-coloured Saturn is below and to the right of Mars and fainter, directly below orange Antares, the brightest star in Scorpio. Saturn is at opposition on the 3rd of June, rising close to the time of sunset and setting near the time the Sun rises. The Moon will be near Jupiter on the 11th and 12th and passing by the Mars-Saturn region on the 17th to 19th.
Low in the west at dusk Sirius, Takurua, the brightest true star, twinkles blue, sets around 9 pm mid-month. It will appear again in the morning sky to help point at Matariki. Canopus Atutahi, the chief of the Maori stars and the second brightest star, is in the southwest. Atutahi is a chief because it can always be seen in the sky, it is a 'circumpolar' star: one that never sets but goes around in circles.
Sirius/ Takurua is the Zenith star of Tahiti and it was used so by the Polynesians. Sirius appears bright both because it is 20 times brighter than the sun, and because it is relatively close at nine light years. Canopus, the second brightest star, is higher in the southwest sky, circling lower into the south later on. Canopus is around three hundred light years away and 13,000 times brighter than the sun but almost of the same spectral type as the Sun. I fell in love with Canopus when I found out that is on board the Voyagers, as a positioning aid. In fact many starcraft carry a special camera called Canopus Star Tracker. Before the magnetic compasses, Canopus was also considered the south star and navigation was made based on its position. And of course Canopus was the navigator of Argo Navis, and is part of the modern constellation of Carina, which used to be part of Argo Navis.
Opposite Canopus, Arcturus is a lone bright star in the northeast, in the constellation of Bootes. Polynesians call it Hokuleʻa, the "Star of Joy". Arcturus is the Zenith star of the Hawaiian islands. Its orange light often twinkles red and green when it is low in the sky. It sets in the northwest in the morning hours.
Crux, the Southern Cross, is south of the zenith. Beside it and brighter are Beta and Alpha
Centauri, often called 'The Pointers' because they point at Crux. Alpha Centauri is the closest naked-eye star, 4.3 light years away. Beta Centauri and many of the stars in Crux are hot, extremely bright blue-giant stars hundreds of light years away. They are members of a group of stars that formed together then scattered. The group is called the Scorpio-Centaurus Association.
Antares or Rehua is marking the scorpion's heart. In Maori this is the asterism of Manaia Ki Te Rangi, the guardian of the heavens, which one of the three names that Scorpius has here. More so, the entire asterism of Scorpius is the the zenith asterism of Aotearoa, the land of the long white cloud. This land is so big compared to the other Pacific islands that it needs an entire asterism to mark its position in the sky.
Rehua is a red giant star: 600 light years away and 19 000 times brighter than the sun. Red giants are much bigger than the sun but much cooler, hence the orange-red colour. Though hundreds of times bigger than the Sun, Antares is only about 20 times the Sun's mass or weight. Most of the star's mass is in its hot dense core. The rest of the star is thin gas.
Red giants are dying stars, wringing the last of the thermo-nuclear energy from their cores. Antares will end in a spectacular supernova explosion in a few million years.
Below Scorpius is Sagittarius, it's brighter stars making 'the British teapot'.
The Milky Way is brightest and broadest in the southeast toward Scorpius and Sagittarius. It remains bright but narrower through Crux and Carina then fades in the western sky. The Milky Way is our edgewise view of the galaxy. The thick hub of the galaxy, 30,000 light years away, is in Sagittarius. Behold the Milky Way Kiwi, a dark patch in the sky resembling a kiwi bird, holding on its head just like a crown, the galactic center. A scan along the Milky Way with binoculars will find many clusters of stars and some glowing gas clouds. Relatively nearby dark clouds of dust and gas dim the light of distant stars in the Milky Way. They look like holes and slots in the Milky Way. There is a well-known dark cloud called The Coalsack by the Southern Cross. Maori call it te Patiki, the flounder. It is around 600 light years away. The dust, more like smoke particles in size, comes off old red stars. These clouds eventually coalesce into new stars.
Then, there are the Clouds of Magellan, LMC and SMC, in the lower southern sky, are luminous patches easily seen by eye in a dark sky. They are two small galaxies about 160,000 and 200,000 light years away. The Large Cloud is about 5 percent the mass of the Milky Way; the Small Cloud is about 3 percent.
Mercury is in the northeast dawn sky. At the beginning of the month it rises two hours before the sun. It sinks lower through the month. Around the 17th it will be left of orange Aldebaran. Further left of Mercury will be the Pleiades/Matariki star cluster just appearing in the dawn twilight. To see it you will have to learn how to count in Maori: First locate Atutahi - in the dawn sky it will floating low in the southeastern sky. Tahi in Maori means One. Then follow along the Milky Way, you will see blue Takurua, Sirius. Rua means two in Maori. Then on the same line, when they will get parallel with the horizon, the three stars from Orion's belt, Tautoru. In Maori, toru means three. Tahi, Rua, Toru. One, two, three. If you join Takurua with Tautoru and extend the line toward north, just passing Taumata Kuku (the Hyades and red Aldebaran) that look like a triangle, following just a little bit more towards north you will find Matariki. At 444 light years away from Earth, Matariki stars are hot, young and blue and with the naked eye you can see six of them, with a pair of binoculars you can see many more. The best view is with a smaller magnification binoculars as they can fit more stars in the field of view. The Pleiades, or Messier 45 are about 100 million years old, being born just after the dinosaurs went extinct on Earth. The light from the Pleiades - Matariki left the cluster almost in the same time as Galileo was pointing his telescope to the heavens.
This concludes our Jodcast for June 2016 at Space Place at Carter Observatory. May you enjoy clear and dark skies so that you can see the stars and always remember that we are made of the same star dust as they are! Kia Kaha and clear skies from the Space Place at Carter Observatory in Aotearoa New Zealand and since the new year will start soon, Nga Mihi o Te Tau Hou.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for May 2016
7 touko 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during May 2016.
Highlights of the month
May 9th - the Transit of Mercury across the face of the Sun
On May the 9th, we will, if clear in the UK, be able to witness the complete passage of Mercury's disc across the face of the Sun. The transit begins soon after 11 hours UT, the midpoint of the transit is at 14:58 UT and Mercury leaves the Sun's disk at 18:42 UT - a total time of 7 and a half hours. This is Mercury's first transit since 2006 and the next will occur on November 11th 2019 but will not be so easily visible from the UK. These are three of the 13 or 14 Mercury transits that occur each century.
Mercury's black disk will appear only 10 arcseonds across so binoculars or a telescope will be needed to observe the transit. If direct viewing is to be made a suitable solar filter must be placed in front of the objective(s). Filters made using Baader Solar Film are probably best. Alternatively, an image of the Sun can be projected onto white card using a small telescope or half binocular. An all metal eyepiece is needed to prevent heat damage and it's probably best to limit the aperture to ~1 inch across using a cardboard mask. Always take very great care when viewing the Sun - it is the only astronomical object that can harm us!
At first glance Mercury's disk might, at just 1/200th of the Suns width, appear as a sunspot, but it will be precisely round, be even darker, will lack a grey penumbra and - of course - it will be moving across the Sun' disk. It will be interesting to watch the ingress and exit of Mercury's disk taking 3 minutes and 12 seconds to do so. Let's hope for clear skies!
May 22nd to June 8th: Mars at its best for 11 years
Mars reaches opposition - that is when the Earth lies between the Sun and Mars and when it will be approximatly due south at midnight (UT) or 1 am (BST) - on the 22nd of May, so it will be visible for most of the hours of darkness. However, it will actually be closest to the Earth and so have its greatest angular size of 18.6 arc seconds some 8 days later on the 30th of May. The angular size at closet approach varies due to the ellipticity of the orbit of Mars (and to a far lesser extent to that of the Earth)and will reach 26 arc seconds during 25,695 AD. At closest approach in 2003, Mars reached an angular size of 25.1 arc seconds, its largest angular diameter for 60,000 years. In July 2018 it will reach 24.2 arc seconds across but for both this opposition and that in 2018, Mars will be very low in the ecliptic and hence at low elevation so that the atmosphere will limit our views of the red (actually salmon pink) planet. Happily, it will be higher in the sky at the opposition of 2020.
To find what should be visible at any time, one can use the Sky &Telescope application.
May: Look for the Great Red Spot on Jupiter
3rd - 00:225th - 21:5210th - 21:0112th - 22:3917th - 21:4819th - 23:2724th - 22:3629th - 21:4531st - 23:24
May 5th and 6th before dawn: The Eta Aquarid Meteor Shower
The Eta Aquarids are one of the finest meteor showers that can be seen from the southern hemisphere, but, in the northern hemisphere, may be glimpsed in the pre-dawn sky in the south-east around 90 minutes before dawn. Pleasingly, this year the peak corresponds to new Moon so there will be no moonlight to hinder our view.
May 7th - one hour before sunrise: Saturn, Mars and Antares
Looking to the South-Southwest in the hours before sunrise, Saturn, above, and Mars, to the upper right, can be seen close to Antares in Scorpius.
May 7th - after sunset: a very thin waxing crescent Moon
If clear at sunset, and given a low horizon in the West-Northwest, you may be able to spot a very thin waxing crescent Moon just 1 percent illuminated. Binoculars may be needed, but please do not use them until after the Sun has set. You may be able to observe the major part of the Moon's surface illuminated by light reflected from Earth - called Earthshine - as seen in the accompanying image taken by the author at the Isle of White Star Party.
May 14th and 27th, evening: The Hyginus Rille
These evenings, should it be clear, are a superb time to view the Hyginus Rill as it will lie close to the terminator. For some time a debate raged as to whether the craters on the Moon were caused by impacts or volcanic activity. We now know that virtually all were caused by impact, but it is thought that the Hyginus crater that lies at the centre of the Hyginus Rille may well be volcanic in origin. It is an 11 km wide rimless pit - in contast to impact craters which have raised rims - and its close association with the rille of the same name associates it with internal lunar events. It can quite easily be seen to be surrounded by dark material. It is thought that an explosive release of dust and gas created a vacant space below so that the overlying surface collapsed into it so forming the crater.
Observe the International Space Station
Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK. (Across the world too for foreign visitors to this web page.)

Note: I observed the ISS three times recently and was amazed as to how bright it has become.

Find details of sighting possibilities from your location from: Location Index

See where the space station is now: Current Position
The PlanetsJupiter
Jupiter is now a little past its best, but still stands out high in the South at nightfall. Its brightness falls slightly from magnitude -2.3 to -2.1 whilst its angular size drops from 41 to 37 arc seconds during the month. Jupiter spends the month below the hindquarters of Leo, halting its retrograde motion westwards across the sky on May 9th. Jupiter sets around 4 am as May begins but by 2 am by month's end. With a small telescope one should be easily able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Gallilean moons as they weave their way around it.

See highlight above.Saturn
Saturn rises in the late evening about 30 minutes after Mars as May begins. Its brightness increases slightly from +0.2 to 0.0 magnitudes during the month whilst its angular size grows to 18.4 arc seconds. Saturn's rings are tilted by 26 degrees from the line of sight - almost as open as they ever get - and span 42 arc seconds. It is moving towards opposition on the night of June 2nd. Saturn forms a triangle with Mars and Antares throughout the month, separated from Mars by 8 degrees as May begins and by 15 degrees at month's end. As Saturn moves slowly across the heavens, it stays at a near constant distance from Antares.

See the highlight above.Mercury
Mercury. The top highlight this month is Mercury's transit across the face of the Sun on May the 9th, but otherwise it will be too dim and low above the horizon to be seen.

See highlight above.Mars

See highlight above. Southern Hemisphere
Haritina Mogosanu from the Carter Observatory in New Zealand tells us about the southern hemisphere night sky during May 2016.
(Atu) Tahi (Taku) Rua (Tau) ToruMy name is Haritina Mogosanu and tonight I am your starryteller from the Southern Hemisphere.
In Maori, tahi, rua, toru means one, two, three.
Three bright planets and the brightest stars share the evening sky this May, and you can see them in three ways when you look at the sky: with the naked eye, with a pair of binoculars and with a telescope. I love each of these methods - they are, each in their own way, very special and each adds a layer of depth to the previous one, which is why I always recommend to people to never buy a telescope unless they have got naked eye stargazing or binocular observing sorted, otherwise it would be too frustrating to look for all these deep sky objects.
So, what can we see with the naked eye in May?
Soon after sunset, circumpolar Atutahi/Canopus, the second brightest star, is southwest of the point directly overhead. Tahi means One in Maori, suggesting that Atutahi is the chief of the stars and visible all night long. Takurua/Sirius, the brightest star, appears northwest of the zenith. Rua means two in Maori and Takurua is one of the two wives of Ra, the Sun. Below Takurua are bluish Puanga/Rigel and reddish Putara/Betelgeuse, the brightest stars in Orion. Between them is a vertical line made of the three stars, Tautoru. Toru means three in Maori and it is the name given to Orion's belt.
The three planets are, in order of appearance, Jupiter, Mars and Saturn.
Midway up the southeast sky are 'The Pointers', Beta and Alpha Centauri. Soon after dusk Arcturus appears in the northeast, often twinkling red and green as the air breaks up its orange light. Golden Jupiter appears in the north. It is the brightest starlike object in May and lights up the night until the early hours of the morning.
Orange Mars comes up in the east just after sunset. It will be at opposition on 22 May, which also means that Mars will be very bright. The term opposition can be a little confusing, but what opposition actually relates to is the way we see Mars from Earth as it sits directly opposite to the Sun with the Earth between them. In May 2016, Mars rises in the east just as the Sun sets in the west. Then, after staying up in the sky the entire night, Mars sets in the west just as the Sun rises in the east. Since Mars and the Sun appear on opposite sides of the sky, we say that Mars is in "opposition". Also, if Earth and Mars followed perfectly circular orbits, opposition would be as close as the two planets could get, but their orbits are neither circular nor coplanar, coplanar meaning in the same plane, so the closest approach between Mars and Earth in almost 60,000 years occurred during 2003.
During opposition, Earth passes between the Mars and the Sun. This only occurs once every 26 months because Earth makes two trips around the Sun in about the same amount of time that Mars takes to make one trip. Sometimes (like now) we will be on the same side of the Sun as Mars (at opposition). Some other time will be on the opposite side. Go figure! And when Mars is on the opposite of opposition it will actually be hidden behind the Sun as it comes between us and Mars, which is the time when communications with Mars are avoided as there is a lot of interference from the Sun.
As the sky darkens, Saturn appears below Mars.
Mercury is very close to the Sun in May so not visible from anywhere in the world with one exception. This is why I will only just mention a spectacular event, which enchants the clear skies viewers from everywhere else but East Asia, Japan, Indonesia, Australia and New Zealand. On Monday, 9 May 2016 starting at 11:15:00 p.m. NZST, most of the world will be able to see the planet Mercury transiting across the disc of the Sun. From Earth, we can only see Mercury and Venus transiting the Sun as these two planets are in between Earth and the Sun. There are about 13 to 14 transits of Mercury in a century and they all occur within a few days from 8 May and 10 November. We will not be able to see this one for the simple reason that it happens during our night time. We can, however still watch it online from New Zealand, as several different webcasts will cover the transit. The event will last for seven hours.
Crux, the Southern Cross, is visible southeast of the zenith, to the right of 'The Pointers', Alpha and Beta Centauri. Zenith refers to an imaginary point directly "above" a particular location, on the imaginary celestial sphere.
Orange Antares, right of Mars, marks the body of Scorpius, the Scorpion. Antares means 'rival to Mars' in Greek for the planet and star are often similar in colour and brightness, but not at this time of year.
The Milky Way, our edgewise view of the galaxy, is brightest in the southeast toward Scorpius and Sagittarius where its centre lies, and it can be traced up the sky past the Pointers and Crux, fading toward Sirius. Its nearby outer edge is by Orion, where the Milky Way is faintest.
The Clouds of Magellan, LMC and SMC, are two small galaxies midway down the southern sky, easily seen by eye on a dark moonless night. If you use your peripheral vision, which means using the edge of your vision out of the corner of your eye instead of looking directly at them, it will reveal more detail. It’s a trick we use in stargazing, and has to do with how our eyes are constructed. Night vision is mostly based on our rod cells (the ones responsible with detecting movement, which is also something we see very well with on the edge of our vision).
Once you've mastered the naked eye observing, it's time to try the next level, binoculars.
What can we see with a pair of binoculars?
Binoculars come in many shapes and forms - a great size for stargazing is 7 x 50 or 10 x 50. The first number is a measure of power, it means how much these binoculars magnify, in this case the 7 and the 10. The second number is the diameter of the objective (the big lenses at the front) in millimeters, in this case the 50. I love binoculars, they are my favourite aids to observing the night sky because they are light, you can take them easily with you on trips and they don't really require assembly or polar alignment. With a tripod attached they are truly magnificent. We have two eyes, so binocular views are more spectacular in many regards than telescopic, because binoculars give depth of view as they engage both eyes in the process.
There are a few great objects that you could admire with binoculars. For instance Jupiter and its four moons. Also on the ecliptic, M44 - the Praesepe in Cancer. Known as the beehive, the open cluster swarms with stars. It is as far as 577 light years away and estimated to be 730 million years old with an average magnitude of 3.5. Also in Cancer, M37 is another open cluster, one of the oldest known, almost 3.2 billion years.
Another good target for binoculars is Leo, marked by the bright Jupiter. Jupiter is 750 million km away, so it is always worth a look. Its four big "Galilean" moons look like faint stars near the planet. One or two can be seen through binoculars. All four are easily seen in any telescope magnifying 20x or more. Sometimes one or more of the moons will be invisible as they pass in front of, or behind, Jupiter. The Moon will be near Jupiter on 15 May. Close to the area south of the triangle that marks Leo's hips, M65, M66 and NGC 3628 will be visible depending on the size of your binoculars. They are also known as the "Leo Trio". Also in Leo, M105 is an elliptical galaxy. Last but not least M96, another galaxy in Leo, lies about 35 million light years away. At the beginning of May Jupiter sets around 2am, reducing to around midnight by the month's end so you might want to look for these objects in the first part of the night.
If all else fails, simply take your binoculars and swipe the milky way from one edge to the other. You might not figure out exactly which objects you are looking at but you will definitely find amazing sights, especially in the region close to Carina. You will find there IC2602, NGC3114, NGC353, NGC2516, that are all open clusters, then in Crux NGC4755 which is another open cluster, NGC2451 in Puppiz, and IC2391 in Vela.
Lower down, Omega Centauri is a globular cluster in Centaurus and in Scorpius, there are the Butterfly Cluster, M7 open cluster and NGC6231 open cluster.
Saturn is a great sight even with a pair of binoculars and this time its rings are near maximum tilt. It is 1,360 million km away. Titan, its biggest moon, orbits four ring diameters from the planet. You might also be able to see Titan with binoculars.
One of my bibles in terms of what to see in the night sky is Philips's Night Sky Atlas, by Robin Scagell and with maps by Will Tirion. Every time someone asks me what telescope to buy, I ask them if they do have a pair of binoculars. If the answer is no, then I always say don't buy a telescope if you have not looked at the sky with binoculars. Even if you only used them to locate objects that are too faint for the naked eye or hidden by light pollution. Some of the best views of the larger star clusters, bright nebulae and comets are best seen with binoculars.
This concludes our Jodcast for May 2016 at Space Place at Carter Observatory. As the Maori say, E whiti ana nga whetu o te Rangi (the stars are shining in the sky) Ko takoto ake nei ko Papatuanuku (whilst Mother Earth lays beneath)
May you enjoy clear and dark skies so that you can see the stars and remember that we are made of the same star dust as they are! Kia Kaha and clear skies from the Space Place at Carter Observatory in Aotearoa New Zealand.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
The night sky for April 2016
1 huhti 2016· The night sky this month
Northern Hemisphere
Ian Morison tells us what we can see in the northern hemisphere night sky during April 2016.
Highlights of the month
April - still a great month to view Jupiter.
This is still a great month to observe Jupiter. It lies in the southern part of Leo, but still reaches an elevations of ~48 degrees when crossing the meridian during the evening. An interesting observation is that the Great Red Spot appears to be diminishing in size. At the beginning of the last century it spanned 40,000 km across but now appears to be only ~16,500 km across - less than half the size. It used to be said that 3 Earths could fit within it, but now it is only one. The shrinking rate appears to be accelerating and observations indicate that it is now reducing in size by ~580 miles per year. Will it eventually disappear?

The features seen in the Jovian atmosphere have been changing quite significantly over the last few years - for a while the South Equatorial Belt vanished completely but has now returned to its normal wide state.
April: Look for the Great Red Spot on Jupiter
The list below gives some of the best evening times during April to observe the Great Red Spot which should then lie on the central meridian of the planet.1st - 23:474th - 21:166th - 22:549th - 20:2411th - 22:0213th - 23:4116th - 21:1018th - 22:4920th - 21:0321st - 20:1823rd - 21:5725th - 23:2530th - 22:44
April 3rd - 22:00 BST: Ganymede emerges from Jupiter's shadow
During the early evening, Jupiter will apear to have just 3 Gallilean satellites: Io and Callisto to its right and Europa to its left. Ganymede is hiding in Jupiter's shadow but will emerge just after 22:00 BST later in the evening.
April 6th: just before dawn - the Moon occults Venus
On the 6th of the month, the Moon and Venus will lie close together low in the eastern sky before dawn. At 08:28 BST, as observed from the centre of the UK, Venus will disappear behind the disk of the very thin crescent Moon whose phase will be just 2%. This will be quite an observing challenge and will need binoculars or a small telesocpe to observe along with a good low eastern horizon. BUT BEWARE NOT TO OBSERVE CLOSE TO THE SUN! If possible stand in the shadow of a wall to the left of your position. Ideally, using an equatorial mount, locate the Moon when it rises at 06:20 BST and continue tracking as it approaches and then occults Venus. As seen from the centre of the UK, it will emerge around 20 minutes later as it briefly passes behind the Moon's northern dark limb. The occultation will not be visible from Scotland and, in the northern part of the UK, Venus will be seen to graze along the Moon's rough northern edge. Venus will take ~60 seconds to disappear and ~70 seconds to emerge. NOTE: to show the occultation graphically, I have had to remove the Sun's glare - this will be a very difficult observation.
April 8th: 45 minutes after sunset - Mercury and a thin crescent Moon
Looking west after sunset and as darkness falls, Mercury will be seen just 6 degrees to the right and slightly up from the a very thin waxing crescent Moon.
April 16th - mid evening: A waxing Moon nears Jupiter
During the evening the Moon will be seen gradually nearing Jupiter, closing in to a separation of just over 4 degrees at 22:00 UT.
April 21st all night: The Moon at apogee
On the 21st the Moon, one day from full, reaches apogee, that is at its furthest distance from the Earth. So, on the following day, it will not appear as big - or as bright - as when the full Moon is at perigee, its closest approach to the Earth. Perhaps surprisingly, its angular diameter at apogee is 12% smaller that at perigee and, should a solar eclipse occur near apogee, the Moon's full shadow may not reach the Earth giving rise to what is called an annular eclipse.
April 16th and 29th: Two Great Lunar Craters
These are two good nights to observe two of the greatest craters on the Moon, Tycho and Copernicus, as the terminator is nearby. Tycho is towards the bottom of Moon in a densely cratered area called the Southern Lunar Highlands. It is a relatively young crater which is about 108 million years old. It is interesting in that it is thought to have been formed by the impact of one of the remnents of an asteroid that gave rise to the asteroid Baptistina. Another asteroid originating from the same breakup may well have caused the Chicxulub crater 65 million years ago. It has a diameter of 85 km and is nearly 5 km deep. At full Moon - seen in the image below - the rays of material that were ejected when it was formed can be see arcing across the surface. Copernicus is about 800 million years old and lies in the eastern Oceanus Procellarum beyond the end of the Apennine Mountains. It is 93 km wide and nearly 4 km deep and is a clasic "terraced" crater. Both can be seen with binoculars.
Observe the International Space Station
Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK. (Across the world too for foreign visitors to this web page.)

Note: I observed the ISS three times recently and was amazed as to how bright it has become.

Find details of sighting possibilities from your location from: Location Index

See where the space station is now: Current Position
The PlanetsJupiter
Jupiter reached opposition on March 8th but this is still an excellent month to observe it - high in the southern sky during the evening. It crosses the meridian at around 23:00 (UT) at the beginning of the month and around 21:00 by month's end. Its brightness falls slightly from magnitude -2.4 to -2.3 whilst its angular size drops from 44 to 41 arc seconds. Jupiter spends the month in south-eastern Leo, moving slowly westwards in retrograde motion. With a small telescope one should be easily able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot (see the highlight above) and up to four of the Gallilean moons as they weave their way around it.Saturn
Saturn rises at ~02:00 (UT) as April begins and a little earlier each night so that by month's end it rises at about 23:00 (UT). Shining at magnitude +0.3 and brightening to +0.2 during the month it lies in the southern part of Ophiuchus some 5.5 degrees up and to the left of Antares in Scorpius. Its diameter increases from 17.4 to 18.1 arc seconds as April progresses. It will be due south in the early hours of the morning at an elevation of ~19 degrees. The beautiful ring system has now opened out to ~26 degrees - virtually as open as they ever become - and measures 40 arc seconds across. It will be best observed near the meridian during the hour before dawn. If only it were higher in the ecliptic; its elevation never gets above ~19 degrees and so the atmosphere will hinder our view of this most beautiful planet. Sadly, as seen from our northern climes, on each successive apparition it will get lower in the sky, so now is the time to emigrate to the southern hemisphere!Mercury
Mercury. This month, Mercury has its best apparition of the year for those of us in the northern hemisphere, shining in the west-northwest during the evening twilight. As April begins, it is low above the horizon, but shining brightly at magnitude -1.5. It reaches greatest elongation (east) on the 18th of April, so is higher in the sky, but its brightness will have dropped to a still bright magnitude 0. Then, its highest altitude at sunset will be ~19 degrees, but Mercury will still be at an elevation of ~10 degrees 45 minutes after sunset. At greatest elongation, its disk will be 7.5 arc seconds across with 38% of the disk illuminated. During the latter part of the month, it fades rapidly down to magnitude +1.5 and disappears into the Sun's glare around the 28th of the month as it moves towards inferior conjunction on the 9th of May - when we will observe a transit of Mercury - one of two major highlights for next month!Mars
Mars. At the beginning of April, Mars rises around midnight (UT). As the month progresses it rises earlier each night so at about 10pm (UT) by month's end. It starts the month in Scorpius, moves into Ophiuchus on the 4th and, as it begins its retrograde motion westwards on April 18th, moves back towards Scorpius which it re-enters on the first of May. Its brightness increases dramatically this month, increasing from magnitude -0.6 to -1.4. At the same time its angular size increases from 12 to 16 arc seconds - the largest it has appeared for some ten years! But as it reaches opposition on the 22nd of May it will subtend over 18 arc seconds. So now is the time to start seriously observing Mars when details such as the polar caps and dark regions such as Syrtis Major should be easily visible in a small telescope on nights of good seeing.Venus
Venus,rises less than half an hour before sunrise at the start of April and could be seen given a low eastern horizon, but it will be unobservable after the 9th or so. However, it will be worth attempring to observe it on the morning of the 6th when it is occulted by a thin crescent Moon as detailed in the highlight above.Southern Hemisphere
Haritina Mogosanu from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during April 2016.
This campfire story is dedicated to Stuart @astronomyblog
Welcome to the month of April. My name is Haritina Mogosanu and tonight I'm your starryteller from Space Place at Carter Observatory in Aotearoa New Zealand.
I love the Milky Way. The Milky Way is the most spectacular feature of the Southern Hemisphere but to say that is such an understatement. The Milky Way is so striking here and I believe that in the absence of a polar star (which I found hard to find in the Northern Hemisphere anyway), people could even orient themselves by the Milky Way. And why not? We can easily see the Milky Way from Wellington, which according to Lonely Planet is the the coolest little capital in the world. But is still a city, which means that it does come with light pollution and from most of the cities of the world we are lucky to see just the brightest stars. Yet I have noticed when walking home at night from the Observatory, from my street I can still see the Galaxy. I call it My City of Stars. There are times when I look up and gaze straight at the center of it. This time of the year just after sunset I can see from the centre to the edge from Scorpius to Taurus, in one glorious panorama.
So in April, my beautiful City of Stars is stretching through the night sky from northwest to southeast. Allow your gaze to wander along this celestial tapestry and you will see the brightest stars. Let's start from West. Lining up onto the celestial river are:Very low on the horizon, Aldebaran - in Taurus, with a magnitude of 0.86. Magnitude is the logarithmic measurement of the brightness of the stars. Logarithmic means that each step of one magnitude changes the brightness by a factor of about 2.512. A magnitude 1 star is exactly a hundred times brighter than a magnitude 6 star, as the difference of five magnitude steps corresponds to 2.512 multiplied by 5, which is 100.Castor and Pollux - in Gemini with magnitudes of 1.93 and 1.14Betelgeuse - in Orion with a magnitude of 0.42Procyon - in the Small Dog, with a magnitude of 0.34And Sirius - in the Big Dog. With a mgnitude of -1.46, Sirius is among the brightest stars in the sky. By convention, the brighter the star, the smaller the number and so some stars and objects have negative magnitudes, like Sirius, or like the International Space Station which can reach up to -6 magnitude, or the full Moon, which has a magnitude of -13. The big dog constellation finally looks the right way up heading also to the western horizon too. From it, turn your gaze left.
Nearby comes Canopus -0.72, the second brightest star in the sky. Canopus is not in the white band of the Milky Way. Standing tall, Canopus is high in the sky. Canopus is a circumpolar star from Wellington, which means that it goes around in circles in 23 hours and 56 minutes, riding the celestial Ferris wheel of the Southern Skies, a giant wheel that never stops, day after day, in a sidereal time cycle, as long as the Earth is turning.
Besides Canopus, there are other stars lighting the gondolas of the big wheel but not each and every gondola has a bright star inside. If Canopus is on the top of the big wheel then just imagine that the diameter of the wheel is from Canopus to the horizon. Looking clockwise from Canopus in the 4 o'clock position on the wheel is the Lone Star, Achernar. Achernar marks the end of the grand river Eridanus, the river-asterism that flows all the way from Orion to the southern world. At 0.4 magnitude it shines bright in a region that seems devoid of other stars. Lower down, a peacock (Pavo) takes a ride on the wheel. It's main star, which carries the mundane name of Alpha Pavonis (which literally means the brightest star in Pavo), is in the 7 o'clock position on the giant turning wheel, almost as if is just hanging on the side.
Following the imaginary curve of the wheel, two very bright stars show up closer to the 10 o'clock position. Firstly, the third brightest star in the sky and our closest neighbour, Alpha Centauri, and then Beta Centauri. They point up at the Southern Cross which is even higher than them in the sky at this time of the year. And one of my favourites, the hypergiant Eta Carinae is somewhere in between Canopus and the Southern Cross. All these stars make the imaginary big wheel.
The sky looks almost devoid of stars anywhere inside my celestial Ferris wheel, with two exceptions. Let's split it in two with a diametral line that links the Alpha and Gamma Crucis, stars of the Southern Cross to lonely Achernar. On the same side as the pointers of the Southern Cross, you will find the Small Magellanic Cloud, a beautiful bright galaxy, that looks to the untrained eye (like mine) like a cirrus cloud hanging in space, 200,000 light years away. On the other side of the semicircle, another galaxy, the Large Magellanic Cloud compensates its loneliness by its size, from 150,000 light years away. These so called clouds that neighbour our galactic presence are visually two thirds away from the Southern cross and one third from Achernar. There is nothing else too bright within the big wheel, maybe because the wheel is inhabited by this giant spider, the Tarantula Nebula that has its nest inside the Large Magellanic Cloud. You can see its beautiful wisps through a telescope, although it is very faint. The tarantula nebula is a star-forming region, also known as 30 Doradus, and according to NASA is one of the largest star forming regions, located close to the Milky Way. About 2,400 massive stars in the center of 30 Doradus produce intense radiation and powerful winds as they blow off material into space.
While the Large Magellanic Cloud is enormous on a human scale, it is in fact less than one tenth the mass of our home galaxy. It spans just 14,000 light-years compared to about 100,000 light-years for the Milky Way and it is classified as an irregular dwarf galaxy. The ESO astronomers believe that its irregularity, combined with its prominent central bar of stars suggests to astronomers that tidal interactions with the Milky Way and fellow Local Group galaxy, the Small Magellanic Cloud, could have distorted its shape from a classic barred spiral into its modern, more chaotic form.
Crux, the Southern Cross, is no stranger to the northern hemisphere and it was entirely visible as far north as Britain in the fourth millennium BC. The Greeks could see it too but since then, the precession of the equinoxes, the wobble of Earth, its gyroscopic dance on the orbit has changed the skies a lot so that now Crux is only visible in the Northern Hemisphere from as far south as 25 degrees latitude north. Florida Keys, Puerto Rico, the islands of the Caribbean, as well as Hawaii are its northern limit of visibility. Near the Southern Cross, there is a dark patch of dust that masks the light that comes from the stars behind it and that is known as the coalsack. Inside the coalsack, the Jewel Box is one of my favourite sights that I visit over and over with the telescope.
Lower down on the path of the Milky Way the two pointers look now as if they are hanging from the Southern Cross. First comes Beta Centauri then the famous Alpha Centauri. For Maori they are also known in a different time of the year as the rope of an anchor. Here in Aotearoa, the Maori have three names for the same asterisms (groupings of stars) at different times of the year. What we know as Scorpius is now called Manaia Ki Te Rangi, the guardian of the skies. The messenger between the earthly world of mortals and the domain of the spirits, Mania also resembles to a seahorse and its symbol is used as a guardian against evil. Often you will see Maori people wearing a greenstone in Maori named pounamu Manaia as a taonga, a necklace.
Lower on the Horizon, at a magnitude of +0.95, red giant Antares shines as the brightest star in Scorpius. Right next to it, its rival, Ares by its Greek name, or Mars as we all know it better, is challenging the giant's red hue with its own red glimmer. This is how Antares got its name, as being the rival of Ares, Ant-Ares, the rival of Mars.
As the Milky Way splits the sky into two sectors, through the northeastern horizon runs the ecliptic, a lower arch, the plane of our solar system bearing the zodiacal constellations. They intersect the Milky Way right on the horizon. First to set on the western horizon, is Taurus and of it, just Aldebaran is left gleaming faintly as it passes beyond the edge of the world. The arch of the ecliptic climbs through Gemini, holder of the two bright stars Castor and Pollux, then higher up, Cancer is almost invisible to the untrained eye, a good peripheral vision training object. Leo, with the Royal Star Regulus is now host to the bright planet Jupiter, then comes Virgo with its bright star Spica, then Libra with Zubenelgenubi and Zubeneschamali the severed claws of Scorpius repurposed into a balance for Justice by the Roman Emperor Julius Caesar. Finally the arch curves down onto the western horizon where Scorpius with red Antares is carrying Red Mars. They appear around 10 PM followed by Saturn about forty minutes later. Mars will brighten steadily through the month as we catch up on it. Its distance shrinks from 118 million km away at the beginning of April to 88 million km away at the end of the month. It remains a small object in a telescope. According to our very own Alan Gilmore who received a lot fan mail about the subject, as probably did all of us, in the mid-month a telescope needs to magnify 130 times to make Mars look as big as the Moon does to the naked eye.
Saturn rises after 10:20 pm NZDT at the beginning of April; around 7:20 NZST by month's end. This also means that daylight saving starts soon and with it we will get an extra hour of sleep. Saturn is straight below Antares. If you have never seen Saturn through a telescope, the hunting season is about to open. A small telescope shows Saturn as an oval, the rings and planet blended. Larger telescopes separate the planet and rings and may show Saturn's moons looking like faint stars close to the planet. The best comment that I hear over and over from people looking through the telescope at Saturn for the first time after the ubiquitous wow is how much Saturn looks like... Saturn. Titan, one of the biggest moons in the solar system, orbits about four ring diameters from the planet. Saturn is 1400 million km away mid-month. Mercury might be seen setting in the bright twilight mid-month. It looks like a lone bright star on the northwest skyline.
This almost concludes our Night Sky South report for April 2016 but before I leave you with the peace of the night sky, I just want to quickly show you only two deep sky objects visually close to Jupiter, currently the luminary of the night sky. Jupiter is in Leo. Neighbouring Leo are Sextans and Hydra. Sextans is a "minor" equatorial constellation, a designation that made me smile. This constellation was actually invented by the famous stellar cartographer Johannes Hevelius to celebrate his sextant, a beloved instrument he used to map the sky. A copy of his famous maps adorns the ceiling of our beautiful library inside Space Place at Carter Observatory. Unknown to Hevelius, inside the celestial Sextant there is a bright galaxy NGC 3115, also known as the Spindle Galaxy. According to NASA, this field lenticular galaxy, several times bigger than the Milky Way, holds the nearest billion-solar-mass black hole to Earth whereas our supermassive black hole at the center of the Milky Way galaxy, called Sagittarius A, has a mass only equal to about 4 million suns.
The other object that I want to show you is inside the largest of the 88 constellations in the sky, Hydra, and close to the current position of Jupiter. The remains of a dying star form a planetary nebula called NGC 3242 and nicknamed "The Ghost Of Jupiter". A planetary nebula is a slowly dying star, a star that is not too big not too small, anything say in the range of 0.8 - 8 solar masses. Planetary nebulae are beautifully coloured and it is believed that they may play a crucial role in the chemical evolution of the Milky Way, blowing out their chemical elements to the interstellar medium. Now these are the same chemical elements that make our bones, construct our skin, and basically are both the building bricks of who we are and what keeps us alive. And all these chemical elements we have on Earth have all been through the hearts of stars. I get many comments a lot of times from people telling me how small and daunted, dwarfed and insignificant they feel when they look at the stars. And that they deliberately avoid looking up. It took me many years to get my head around this but when I look up to the sky, I know for sure that I am made of stardust, and that makes me glow every day.
From Space Place at Carter Observatory here in the southern hemisphere I wish a you clear and dark skies so that we can always see the stars and remember that we are made of the same stars dust as they are.
Special Thanks go to the amazing Rhian Sheehan, Peter Detterline, Chief Astronomer of the Mars Society, Alan Gilmore from University of Canterbury and to Toa Nutone Wii Te Arei Waaka from the Society for Maori Astronomy and Traditions.
- Kuuntele Kuuntele uudestaan Jatka Soittaa...
- Kuuntele myöhemmin Kuuntele myöhemmin
Näytä enemmän

Episodit

The night sky for December 2017

The night sky for November 2017

The night sky for October 2017

The night sky for September 2017

The night sky for August 2017

The night sky for July 2017

The night sky for June 2017

The night sky for May 2017

The night sky for April 2017

The night sky for March 2017

The night sky for February 2017

The night sky for December 2016

The night sky for November 2016

The night sky for October 2016

The night sky for September 2016

The night sky for August 2016

The night sky for July 2016

The night sky for June 2016

The night sky for May 2016

The night sky for April 2016