To help you learn about the southern night sky, Sydney Observatory provides an audio guide/podcast, transcript of that audio, and a sky map or chart each month. This month’s guide is presented by Melissa Hulbert, Sydney Observatory’s Astronomy Education Officer.
Mel takes us on a tour of the stars and constellations prominent in the February sky, including letting us know about a very close encounter between the Moon and Jupiter on the night of 18th February, as well as when to see Venus in the morning sky. Mel also tells us about Comet PanSTARRS, discovered in June 2011, and which will hopefully be visible again in February, with best viewing likely in the dawn sky for Southern Hemisphere observers.
For this and more, listen to the February 2013 night sky guide audio, or read the transcript below.
SEE THE SKY CHART
We provide an embedded sky map (below – please be patient as it can take a little while for it to load) and a February 2013 night sky chart (PDF) which shows the stars, constellations and planets visible in the night sky from anywhere in Australia. To view PDF star charts you will need to download and install Adobe Acrobat Reader if it’s not on your computer already.
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BUY THE BOOK
Our annual book, ‘The 2013 Australasian sky guide’ by Dr Nick Lomb has more information and star maps for months from December 2012 until December 2013 inclusive, plus information about the Sun, twilight, the Moon and tides, and a host of other fascinating astronomical information. You can purchase it ($16.95) at Sydney Observatory and Powerhouse Museum shops or other good bookshops, or online through Powerhouse Publishing (additional packing/postage costs apply).
READ THE TRANSCRIPT (after the jump)
Transcript of the February 2013 monthly sky guide audio
Hello and welcome to the night sky for February. My name is Melissa Hulbert and I’m an Astronomy Educator at Sydney Observatory.
Before we start our night sky tour, make sure you download the February sky map from our website at www.sydneyobservatory.com.au. Click the ‘Astronomy’ tab, and go to the ‘Monthly sky guides’ section.
Armed with your sky map and a small torch with some red cellophane covering it, find a nice dark place away from the glare of the street lights and make sure you know your cardinal directions – that’s north, south, east and west. Remember that the Sun rises in the east, moves through the northern sky during the day and sets in the west; or a small compass will also point you in the right direction. Pick a comfortable spot either on a rug or a deck chair that you can lay back in. Wait about 5-10 minutes and allow your eyes to adapt to the darkness.
Now let’s turn towards the north. High in the northern sky is the familiar constellation of Orion, the Hunter. In Greek mythology, Orion was a hunter of great skill and boasted that he could kill all living animals. Gaea the Earth goddess was alarmed by his statement and, fearing for all the animals on Earth, she sent a scorpion to kill him. Orion was stung on the shoulder but was later revived and placed in the stars along with the scorpion. This entire myth is played out in the stars each year. As Scorpius the scorpion rises in the east, Orion sets in the west defeated. When Scorpius sets in the west the healer Ophiuchus crushes the scorpion into the Earth and revives Orion so he can rise in the east again. Orion appears in many cultures, even the ancient Egyptians saw Orion as Osiris, god of the underworld and of regeneration.
If you’re having difficulty picking out the hunter then look for ‘The Saucepan’. This is a familiar group of stars for those of us in the Southern Hemisphere and is Orion’s belt and sword. Orion is upside down for us. Below ‘The Saucepan’ you should see the red supergiant star, Betelgeuse. Remember the scorpion’s sting? Betelgeuse has a distinct reddish tinge to our eye and is the shoulder or armpit of Orion. Above ‘The Saucepan’ and diagonally opposite Betelgeuse is a brilliant white star – Rigel, one of Orion’s knees. Rigel is a blue-white supergiant star which is about 60,000 times more luminous than our own Sun. Rigel also has a small companion star which is best seen through a telescope though if seeing conditions are not the best, small telescopes will struggle to see the companion through the glare of Rigel.
Let’s return to the belt of Orion and follow its line to the west where we come to the back of a sideways ‘V’. This ‘V’ is the head of Taurus the bull who appears to be charging at Orion.
Taurus, like Orion, is also steeped in Greek mythology and represents the bull Zeus changed into to carry Princess Europa off to Crete.
Back to the ‘V’ which is part of a large open star cluster visible in binoculars called the Hyades. One of Taurus’ eyes is an orange giant star called Aldebaran which means ‘the follower’ and it too has a distinct orange tinge when viewed with the unaided eye. It follows the Pleiades, a wonderful open star cluster that can be seen with your eyes to the north-west of the ’V’. The Pleiades are known as the ‘Seven Sisters’ as seven stars are readily seen with your eyes, but away from city lights, up to 13 can be seen with the unaided eye. The whole cluster contains about 100 stars and binoculars are the best way to view this marvellous object.
Make your way back to Orion’s belt and this time, follow the line of the belt in the opposite direction, towards the east. Here we come straight to a very bright white star. This star is called Sirius and is the brightest star in either Southern or Northern Hemisphere. It is bright because it is close to us – only 8.7 light years away or about 87 million million kilometres from us (and that’s considered close).
Sirius features strongly in mythology. To the Greeks it was the canine companion of Orion, but could also be Hermes, the guide to the dead. To the ancient Egyptians, Sirius originally represented Anubis who invented embalming and funeral rites, and guided you through the underworld to your judgement and helped weigh your heart to determine your fate in the afterlife. Later Sirius represented the goddess Isis and the Egyptians initially based their calendar on Sirius’ yearly motion around the sky.
Sirius is the brightest star in the constellation of Canis Major or the Great Dog and perhaps is best known to our younger listeners as a character in the ‘Harry Potter’ books who is able to change into a large dog.
Let’s do an about-face and turn to look at the southern sky. High in the south is a bright star, in fact the 2nd brightest in our sky – Canopus. Canopus is a white supergiant star and is 313 light years away. Canopus was the helmsman of the Greek King Menelaus and rather appropriately is now used by spacecraft as a navigational guide.
Canopus is the brightest star in the constellation Carina, which represents the keel of a boat. Originally it was part of the large constellation Argo Narvis which was the Ship of the Argonauts, which Jason and the Argonauts used in their quest for the Golden Fleece. So, nearby you will see Vela the sails and Puppis the poop. In 1793 Argo Narvis was divided into the three constellations we see today.
If you are away from city lights you might make out two cloud-like shapes in the southern sky. A large one almost straight overhead in the southern sky and a smaller one a little lower and to the west. These are the clouds of Magellan, but they are not clouds. They are companion galaxies to our own Milky Way. They are gravitationally attached to our galaxy and we now know there is physical interaction between these galaxies and our own.
So what else can we look forward to seeing in the sky in February 2013?
This month after sunset, look low towards the west horizon and you will see two star-like objects in the twilight. The first is the planet Mercury, which is often hard to see due to its proximity to the Sun. It does have a close encounter with Neptune on the 6th and 7th when the pair will be only one degree apart, however you will need binoculars to see the elusive Neptune. This will be a good chance to see Neptune as it can be difficult to locate in the sky. Just to the west of Mercury is our second star-like object, Mars. Mars’ distinct reddish-orange hue makes it easier to indentify. Mercury and Mars are at their closest on the 8th and 9th. With all three planets low on the horizon and in twilight, binoculars will help in spotting all three. On the 12th, a thin crescent Moon will be visible to the east of Mercury.
High in the north-west sky is Jupiter. It is easy to find as it is the brightest object in that area of the sky. It is in the constellation Taurus and is between the open star clusters:- Hyades and Pleiades. Binoculars will show you the four largest moons known as the Galilean satellites and small aperture telescopes will show one or two of the Jovian clouds belts.
On the 18th a very close encounter between the Moon and Jupiter will occur. If we draw a line from Bega, NSW to Carnarvon, WA then anyone south of this line should see Jupiter occulted by the Moon. This will be a spectacular sight as the Moon’s phase is first quarter and only part (or half as we see it from Earth) is illuminated. The part of the Moon that is unilluminated is where the occultation starts. First Ganymede (the largest of the Galilean satellites) will disappear then Jupiter, followed by Io, Callisto and finally Europa and they will then reappear in the same order from the illuminated side of the Moon. This is only a rough location guide and for some locations this event will be very close to the horizon. If you are north of this approximate line then you won’t miss out, you will see Jupiter approach the north pole of the Moon, a spectacular sight in itself.
In the north-east and rising around mid-evening is the wonderful ringed-planet, Saturn. Saturn’s impressive ring system can be seen in even small aperture telescopes and depending on the telescope you are using you may even catch a glimpse of a few of Saturn’s moons including the second largest in our solar system, Titan.
February has Venus on offer for all you early-birds! It will only be visible for the first half of the month after which it is too close to the Sun to be seen. It will remain lost in the Sun’s glare until early May when it returns to the evening sky.
I do have one wildcard for you this month – Comet PanSTARRS (C/2001 L4). This comet was discovered in June 2011 and at that time was about 1,182 million kilometres away with a magnitude of +19, so quite faint. During February and March the comet will hopefully be visible both in the evening twilight and in the dawn sky. Best viewing will likely occur in the morning sky for Southern Hemisphere observers. PanSTARRS is estimated to reach a peak magnitude anywhere from +1 to -1, so easily seen with the unaided eye. After mid-March the comet is close to the setting Sun so conditions will not be ideal for observing.
Of course this is all based on predictions and comets are notoriously unpredictable which reminds me of that famous quote by renowned comet hunter David Levy: “Comets are like cats. They have tails, and they do precisely want they want.”
Wishing you clear skies and see you next month under the stars!
If you have enjoyed this podcast and think you might want to regularly check out what’s in the night sky, why not purchase a copy of Sydney Observatory’s book the ‘Australasian Sky Guide’ for 2013. It not only contains detailed monthly sky guides, but is jam-packed with astronomical information including rise and set times for the Sun, Moon and planets, tides and a detailed look at our Solar System and upcoming astronomical events. Only $16.95 from Sydney Observatory and Powerhouse Museum shops or you can purchase it online (additional costs apply).
You can also subscribe for free to our Sydney Observatory monthly sky guide podcasts through iTunes.
This has been Melissa Hulbert from Sydney Observatory with the February 2013 sky guide podcast.