The Night Sky This Month

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Ian Morison tells you what can be seen in the night sky this month.
Updated: 10 hours 25 min ago

The night sky for February 2018

Tue, 06/02/2018 - 09:00
Northern Hemisphere

Ian Morison tells us what we can see in the Northern Hemisphere night sky during February 2018.

  • Jupiter - Jupiter rises around 2 am at the beginning of the month and just before midnight by month's end. Initially it has a 36 arcsecond disk, shining at a magnitude of -2 but as the month progresses, its apparent diameter increases to 39 arcseconds and it brightens to magnitude -2.2. Jupiter will transit before dawn and so will enable the giant planet to be seen with the equatorial bands, sometimes the Great (but reducing in size) Red Spot and up to four of its Gallilean moons visible in a small telescope. Sadly, Jupiter, lying in Libra during the month, is heading towards the southern part of the ecliptic and will only have an elevation of ~20 degrees when crossing the meridian. Atmospheric dispersion will thus hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Saturn - Saturn, at the start of its new apparition, rises at around 5 am at the start of the month and just after 3 am at its end. With an angular size of ~15.5 arc seconds it climbs higher before dawn and so becomes easier to spot as the month progresses. Its brightness remains at +0.6 magnitudes. The rings were at their widest a few months ago and are still, at 26 degrees to the line of sight, well open. Saturn, lying in Sagittarius, is just 3 degrees above the topmost star of the 'teapot'. Sadly, even when at opposition later in the year it will only reach an elevation of just over 15 degrees above the horizon when crossing the meridian. Atmospheric dispersion will thus greatly hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Mercury - Mercury passes through superior conjuction (between us and the Sun) on the 17th February so will be lost in the Sun's glare until the very end of the month when it might just be glimpsed after sunset with its ~5 arc second disk having an unusually bright magnitude of -1.5.

  • Mars - Mars starts the month moving quickly eastwards in Scorpius close to Beta Scorpii (Graffias) but moves into Ophiuchus on the 8th of the month. 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 which increases from +1.2 to +0.8 and an angular size of just 5.6, increasing to 6.6, arc seconds so no details will be seen on its salmon-pink surface. It will only reach an elevation of ~14 degrees before dawn at the start of the month and just 12 degrees by month's end.

  • Venus - Venus passed through superior conjunction (on the far side of the Sun) on January 9th and so, at the beginning of February will be lost in the Sun's glare, setting less than half an hour after the Sun. However, by month's end, shining with a magnitude of -3.9, it will set around an hour after the Sun and its 10 arc second disk should be easy to spot 30 minutes or so after sunset. However a low western horizon will be needed as it will then only have an elevation of ~5 degrees some way to the south of west.

  • Highlights
  • February 8th before dawn: A waning Moon close to Jupiter - with Mars nearby. If clear before dawn on the 8th, a waning moon between Full Moon and Last Quarter lies close to Jupiter. Down to the left is Mars lying above Antares in Scorpius.

  • February 9th before dawn: Mars and a waning Moon. If clear before dawn on the 9th and looking to the South-southeast, Mars, at magnitude +1, will be seen to the lower right of a waning crescent Moon.

  • February 17th after sunset: Venus and a thin crescent Moon. Looking West-Southwest after sunset on the 17th and given a very low western horizon, one might be able to spot Venus at the start of its new evening apparition. A very thin crescent Moon, just two days after new, will be seen up to its left. Binoculars may well be needed, but please do not use them before the Sun has set. A very tough observing challenge!

  • February 23rd/24th evening: The Moon in a beautiful skyscape. In the evenings of the 23rb and 24th of the month, the Moon, coming towards first quarter, will pass through Taurus and Orion. On the 23rd, it will lie close to Aldebaran and on the 24th lie above Orion.

  • February 6th and 22nd evening: The Hyginus Rille. 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.

  • In her final broadcast for the Jodcast, Claire Bretherton from the Carter Observatory in New Zealand tells us what we can see in the Southern Hemisphere night sky during February 2018.

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

  • Lunar Eclipse - Whilst the Earth blocks all direct light from the Sun, some light passes though the Earth's atmosphere and is bent or refracted towards the surface of the Moon. Light with shorter wavelengths, towards the blue end of the spectrum, is scattered more strongly, so only the redder light gets through, giving the eclipsed moon a telltale reddish glow.

  • Partial Solar Eclipse - Whilst New Zealand won't see it, some parts of the southern hemisphere will also experience a partial solar eclipse this month, on the morning of the 16th NZ time. From parts of Chile and Argentina the moon will cover some 25% of the Sun's disk, whilst from Antarctica around 49% will be covered.

  • Orion - Orion is now high in the north after dark, with Sirius, or Takurua, the brightest star in our night-time sky, even higher.

  • Procyon - 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.

  • Clusters and Nebulae - 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 in long exposure photographs.

    Below Canis Minor sits 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 ways 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 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.

    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. It 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.

  • Planets - Our evening skies are still bereft of bright planets. Jupiter is the first to rise at around 1 am at the start of the month. Mars follows shortly afterwards, and the two are joined by Saturn around 3:30 am. You may spot Mercury briefly at the start of February, rising in the dawn twilight around an hour before the Sun, but it will soon disappear from view as it heads back towards the Sun. By months end Jupiter has moved into our evening skies, rising at 11 pm, Mars around 12:30 am and Saturn by 2 am, making a diagonal line down the eastern morning sky.

  • Farewell - After 8 years at Space Place at Carter Observatory, and being involved with the Jodcast for almost as long, I am moving on to a new role in February and so sadly this will be my last southern skies section. It's been a great pleasure bringing you a little taster of our wonderful New Zealand stars and some of the amazing stories within them over the past few years. I wish you clear skies and all the very best for the future. So farewell from me, Claire Bretherton, and the team here at space Place at Carter Observatory.

  • The night sky for January 2018

    Mon, 08/01/2018 - 20:00
    Northern Hemisphere

    Ian Morison tells us what we can see in the northern hemisphere night sky during January 2018.

  • Jupiter. Jupiter is now a pre-dawn object rising some three and a half hours before the Sun at the beginning of the month with its 33 arc second disk, shining at a magnitude of -1.8, to be seen under clear skies. As the month progresses, its apparent diameter increases to 35.8 arc seconds and it brightens to magnitude -2. The elevation before dawn will then be sufficiently high to enable crisp views of the giant planet to be seen with the equatorial bands, sometimes the Great (but reducing in size) Red Spot and up to four of its Galilean moons visible in a small telescope.

  • Saturn. Saturn passed behind the Sun on December 21st (superior conjunction) on December 21st and reappears in the pre dawn sky this month at the start of its new apparition. It is unlikely to be seen in the first week of January, but climbs higher and so becomes easier to spot as the month progresses as its brightness increases to +0.6 magnitudes. The rings were at their widest a few months ago and are still well open.

  • Mercury. Mercury reaches greatest elongation west on New Year's Day shining at magnitude -0.3. It will be seen low in the Southeast before dawn and will be visible for a couple of weeks before sinking back towards the Sun. Its angular diameter reduces from 6.7 to 4.9 arc seconds but, as the percentage illuminated surface area increases from 62% to 95%, its brightness remains constant throughout the month.

  • Mars. At the start of the month Mars lies in Libra but moves down into Scorpius at the end of the Month. 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 1.5 to 1.2 and an angular size of just 4.8, increasing to 5.6, arc seconds so no details will be seen on its salmon-pink surface. Moving eastwards, Mars has a very close conjunction with Jupiter on the 6th of January.

  • Venus. Venus, passes through superior conjunction (on the far side of the Sun) on January 9th and so cannot be observed this month.

  • Highlights
  • Around the 17th of January (with no Moon in the sky): find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum Around new Moon (17th January) - 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).

  • January 5th before dawn: A waning Moon closes on Regulus in Leo. If clear before dawn on the 5th, a waning Moon between Full Moon and Last Quarter lies just a few degrees from Regulus in Leo.

  • January 6th before dawn: Mars and Jupiter up close. If clear before dawn on the 6th and looking to the South-Southeast, Mars, at magnitude 1.4 will be seen just to the right of Jupiter shining at magnitude -1.8. At their closest they will be just 23 arc seconds apart.

  • January 13th before dawn: Saturn and Mercury. Looking Southeast before dawn on the 13th and given a very low eastern horizon, one might be able to spot Saturn at the start of its new apparition lying just above Mercury. A very thin crescent Moon will be seen up to their right. Binoculars may well be needed but please do not use them after the Sun has risen.

  • January 26th: Two Great Lunar Craters. This is a great night to observe two of the greatest craters on the Moon, Tycho and Copernicus, as the terminator is nearby.

  • Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during January 2018.

    This month we will continue our tour of some of the clusters and nebulae along the Milky Way, which stretches across the eastern sky after dark, becoming brightest in the south towards the Southern Cross /Te Punga.

  • Orion still dominates our Eastern skies after dark. Just above and to the right of Sirius, at distance of around 4 degrees, is M41, or NGC 2287. M41 is an open cluster of stars, covering an area around the size of the full moon. It is just about visible as a blurry smudge to the naked eye from a clear, dark location. Through binoculars or a small telescope you will start to resolve a number of individual stars, showing hints of red and orange, including a prominent 6.3 magnitude K3 giant close to the cluster's centre.

  • Canopus. Canopus is the brightest star in the constellation of Carina, the keel, which along with Vela, the sails, and Puppis, the poop deck, once formed part of the southern constellation of Argo Navis. Straddling the Milky Way, this represented the great ship used by Jason and the Argonauts in their search for the Golden Fleece. The constellation was split into the three components used today by French Astronomer Nicolas Louis de Lacaille in 1763.

  • Eta Carina. Eta Carinae is now back to around 4th magnitude, but it is brightening again. It is expected to end its life in a huge supernova within the next few thousand years.

  • Nebulae in Eta Carinae. Also worth looking out for in Carina is NGC 2516, known as the southern beehive, located just above the false cross, and NGC 3532, the football cluster, or wishing well cluster. Both are visible to the naked eye, but a good pair of binoculars will reveal a stunning view. NGC 3532 in particular is a great target, a favourite of English astronomer John Herschel, and the very first object to be observed by the Hubble Space Telescope in May 1990. You'll find it roughly half way between Crux and the False Cross, close to Eta Carinae.

  • Planets. Mercury sits low in the morning twilight throughout most of January and is soon joined by Saturn, with the two sitting right next to each other on the morning of the 13th. Saturn continues to rise higher whilst Mercury, on its inner orbit, sinks back into the twilight.

  • Wishing you clear skies, and a very happy 2018, form the team here at Space Place at Carter Observatory.

    The night sky for December 2017

    Mon, 04/12/2017 - 19:00
    Northern Hemisphere

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

    The Planets

    • Jupiter - 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.

    • Highlights
    • M31 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.

    The night sky for November 2017

    Tue, 07/11/2017 - 11:00
    Northern Hemisphere

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

    The Planets

    • Jupiter

      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.

      HIGHLIGHTS
    • November - 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:

      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 (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.