Article written by: Helen McLoughlin, Education Officer
Let’s face it, New Year’s Resolutions like ‘I’m going to the gym three times a week’ or ‘I’m going on a diet’ are all well and good but fizzle out after a week or two. Why not take up stargazing once a month and discover the wonders of the night sky? The good news is that January’s celestial delights are a great place to start for new stargazers!
We are starting this year off with a spectacular shooting star display! If you stayed up late on the 3rd of January you might have witnessed the magnificent Quadrantid meteor shower. This meteor shower is dust particles from the old comet 2003EH1, which are burning up in the Earth’s atmosphere. This shower of shooting stars is named after Quadrans Muralis, a now defunct star group that used to lie in the space between our present-day constellations of Boötes and Draco. There was no moonlight to interfere with this meteor shower so I hope many of you were out having a ‘meteor party’ and enjoying our first meteor shower of the year!
If you missed the meteor shower, don’t worry, there’s more exciting events to feast your eyes upon. Like on the night of the 20/21 January we are treated to the most stunning eclipse that we will see from our location this year. It is the lunar eclipse in which we will see an unusually large and bright supermoon being engulfed by the Earth’s shadow. Total lunar eclipses occur when the Earth passes between the Moon and the Sun, blocking the Sun’s light and casting a shadow over the Moon. This year it just by chance coincides with a ‘supermoon’. There is a catch however, as the eclipse will begin at 3.34am and its totality lasts from 4.41am to 5.43am. So get the date in your diary and get your alarm set!
As well as these events there are plenty of constellations to look out for in the southern sky. Let’s start out by looking at Orion’s two attack dogs, Canis Major and Canis Minor. Forget about Rudolph having a very shiny nose, as Canis Major (the Great Dog) has the shiniest of them all! This constellation has the honour of having the brightest star in our night sky, Sirius, marking Canis Major’s nose. Sirius is only about 20 times brighter than our Sun, while Rigel, in the constellation of Orion, is 60,000 times brighter. So why is Sirius the brightest star in our night sky when there are other brighter stars out there? Well, Sirius is very close to us at only 9 light years away, whereas Rigel is more than 100 times further away so does not appear as bright to us. Sirius has a magnitude of about -1.5. It is a binary star in which the brighter star is a main sequence star and its companion is a dense “white dwarf” star that orbits its larger companion every 50 years. To find Sirius, use Orion’s belt to trace a diagonal line down towards the horizon. This will point you in the right direction of the dog standing on its hind legs.
Moving upwards we come to Canis Major’s little companion, Canis Minor (the Little Dog). While it is easy to imagine Canis Major as a dog, we have to use our imagination to see the little dog as it is a straight diagonal line joining two stars! One of these stars is called Procyon meaning ‘before the dog’ as it appears to rise above the horizon before the dog star, Sirius. Procyon is another very bright star in our sky. It is not extraordinarily bright but again like Sirius, it is relatively close to us at around 11 light years away. With all these bright stars in the night sky, there is really no excuse not to go looking for them this winter!
Now let’s turn our attention to the planets. During January, Mars is the only prominent planet in the evening sky. (Finally, we have a celestial object with more sociable hours!) Shining at a magnitude of +0.7, it sets around 11.30pm. Most of the action in terms of planets however does take place in the early hours before dawn. The dazzling Venus rises around 4.30am but the important date for your diary is 6th January as this is when Venus reaches its greatest eastern elongation of 47 degrees from the Sun. Venus’s orbit lies closer to the Sun than the Earth’s, meaning that it always appears close to the Sun and so can be difficult to observe when it gets too close. However, during these moments of great elongation, Venus will be at its further from the Sun and so at its highest point above the horizon in the morning sky before the Sun has risen. To find it, look for a bright object in the eastern sky before sunrise. If the sky is clear you can’t miss it!
And to top off a great month of watching the wonders of the sky, we have the crescent moon passing Jupiter and Venus on the 30th and 31st January. Venus and the 25-day old moon will be just 6 arcminutes apart at closest approach so will be close enough to both fit within the field of view of many telescopes. But they will also be clearly visible to the naked eye or through a pair of binoculars. The table below shows the positions of Venus and the Moon at the moment of their conjunction:
There you have it, a quick rundown of the highlights of the January Night Sky. So get your winter warmers on, get out there and beat those January blues with some star and planet gazing!