January sees the beginning of a New Year with everyone’s New Year’s resolutions to be healthier, to be happier and many people deciding to take up or return to a fun hobby from the past! With that I guarantee many are toying with the thought of lifting up those binoculars and searching out the telescopes to begin a new stargazing year! Well I urge you to quit dabbling with the idea but do it, 2013 is a year filled with excellent potential for some extremely fascinating and can’t miss moments, in particular towards the end of the year when we see the promising Comet ISON predicted to be 15 times brighter than our natural satellite, the Moon! But let’s keep our eyes focused on the January night sky and see what the winter night has to offer to begin a hopefully ‘stellar’ 2013!
The winter sky is my favourite season to stargaze, not just because one can find use for the multiple scarves, gloves and bobbly hats you may have discovered under the tree over Christmas but because all the big glittering show stoppers are out to entertain! So to start off the star hoping this month we are going to start off with an old favourite looking towards the south, Orion the hunter. Now hopefully you have read previous blog entries on this dominant star pattern in the winter sky because we are just here for a little stop, as it is the hunter’s quick feet we are interested in, more particular the right foot marked by the bright blue-white supergiant Rigel. This is the fantastically bright star we will begin with to mark out the famous ‘Winter Circle’ or as some people call it the ‘Winter Hexagon’ as it may not be the most spherical circle imaginable. There are six stars that create this irregular circle and we will begin with Rigel, the brightest star in Orion. Quite an impressive star itself with an apparent or visible magnitude of 0.12 but with a whopping absolute magnitude of -7.84! (Remember the lower the designated number the brighter the star.) Rigel is so bright it is 130,000 times more luminous that our own Sun! But as you may find as we work our way around the stellar ‘cast’ of the Winter Circle, these very bright stars can sometimes be more than just one star, such as Rigel which is actually a triple star system working together to provide such a beautiful twinkle in our night sky.
Now, using Rigel, move upwards and slightly to the right to the next very bright star in the sky, Aldebaran. Aldebaran is the brightest star in the constellation of the zodiac sign Taurus the Bull and it has an extra easy signpost to it location during the middle of the month as the gas giant Jupiter is hovering slightly above and to the right of its location. Jupiter itself appears very bright in the night sky and is extremely hard to miss, being one of the most noticeable things in the sky for a while now. So essentially look for two bright objects together in the sky and the dimmer of these will be ‘the Follower’, Aldebaran. Aldebaran is nicknamed the follower due to the fact it appears to constantly chase the very famous Pleiades star cluster across the night sky. Aldebaran works quite hard to brighten our sky as it is one of the few stars in the Winter Circle that is not a binary star but rather it is a red giant star that has moved off its main sequence in life after exhausting it’s supply of hydrogen and ballooned to a massive size, 44 times that of our Sun! With an apparent magnitude of 0.87 its visibility is also aided by the fact it is only 65 light years away from us.
From Aldebaran we can hop to the next star in the circle. Trace upwards and slightly to the left, about the same distance between Rigel and Aldebaran, and your eyes should be resting on the very bright star Capella representing the peak of the Winter Circle. Capella is a very bright star, in fact like all the stars in the Winter Circle it is the brightest star within its constellation, Auriga. It is also the 6th brightest star in the Northern Hemisphere. Capella is an impressive collection of 4 stars in 2 binary stars with one set on their way to becoming giant stars and the other pair being relatively cool dwarf stars. It is located a little bit closer to us than Aldebaran being only 42.2 light years away which will also make it appear much brighter to us.
Now we can begin the descent down from the peak of the Winter Circle towards the lower left at a roughly 45 degree angle, directly south. Once you find yourself hovering in this area search for the very bright ‘head’ star of one of Gemini the twins, essentially of the brighter twin, Pollux, of which this star is named after. This giant orange star is the brightest in the zodiac constellation of Gemini with an apparent magnitude of 1.14 and like other stars within this clique of stars; it has exhausted its supply of hydrogen and has evolved into a very bright and tumultuous giant star! It is located only 33.78 light years away from us and has provided very exciting in our search for extrasolar planets, or more commonly known, exoplanets; planets found outside our solar system, with a planet discovered to be orbiting the bright star.
So moving downwards and ever so slightly to the left, nearly opposite to Aldebaran, you will be within the constellation of the Little Dog, Canis Minor and the bright star of Procyon, the brightest star in the tiny constellation, which is not very hard considering it is made up of just 2 stars. But this should not take away from the impressive feat of stellar brightness that Procyon holds. Located 11.46 light years away it is the 8th brightest star in the northern hemisphere. It’s closeness to our Solar System and Sun aids to its visible brightness. It has another companion star that is much smaller that was not discovered until the late 19th Century because the wobble from the star hid it!
Last but not least we have one of the most impressive stars in the night sky, the ‘Dog Star’. And no this is not the other star that makes up Canis Minor but rather is the collar star on Canis Major, the Great Dog, Canis Minor’s companion in the sky. Its real name being Sirius, aptly named when you learn it is a Greek term meaning ‘scorching’ as this is the brightest star in the night sky. It has the apparent magnitude of 0.12 and has also been nicknamed the rainbow stars because it appears to flicker a multitude of colours but this is due to the brightness of the star and how our atmosphere distorts light. This effect of twinkling colours has given Sirius a bit of a reputation, with many people spotting it and believing it to be a UFO! It is also located a mere 8.48 light years away but it is moving ever so slightly closer to us and will get brighter and brighter over the next 60,000 years!
Now you have discovered and pinpointed all six of the Winter Circle stars you may well see that this is not the most perfect circle in shape but if applied in a different context would most definitely be an excellent circle as it completely encircles the fantastic Orion Constellation, framing the majestic constellation in the night sky. Although the Winter Circle is not as simple and easy to trace and spot as the Summer Triangle it offers drastically more to the star gazer with both stars and constellations within it and all the hidden gems within and around it. As pointed out with Aldebaran it has the glittering jewel in the shape of our largest planet Jupiter floating alongside it this month and even a good pair of binoculars and a clear night can reveal this beautiful planet and its 4 Galilean moons. As well as that if you move further west from Jupiter a clear sky should allow the observing of the beautiful Pleiades star cluster marking the shoulder of the Mighty Taurus the Bull. Just be careful not to wonder too far away from the circle if trying to star hop around it, there are many diversions and attractions that are out to distract you!
The winter night sky, as you may have noted is a good time to spot some of the planets, especially that of Jupiter, but also that of Saturn. Saturn spotting this month will require some late night star gazing with it rising above the eastern horizon before 2 and getting higher so there are many hours watch this beautiful planet rise into the morning sky and begin its descent just as the sun rises. And on the 15ht you can watch a waning crescent Moon follow the gas giant in the night sky!
Well hopefully we have crisp, clear January night skies to kick off a wonderful year filled with stargazing wonders for both the experienced and brand new stargazers out there as there will be lots to put in the event books in 2013. And remember January is the BBC Stargazing month and for any locals there is a stargazing event in Northern Ireland at the Lough Neagh Discovery Centre where you can go to ask stargazing questions and look at the stars as well as learn lots of other science and stargazing extras at this very interactive event for all ages! For details click this link. For any who can’t make it out to any local BBC Stargazing events there is live coverage of stargazing hosted by the charismatic Brian Cox and Dara O Briain on BBC2, details of which is in the BBC Stargazing website located at the link here.
(Article by Kerry Scullion, Education Support Officer)