Better late than never, here is a round up of starry night sights for January:
Welcome to another year of astronomical observing prompts and miscellany, which gets off to a cracking start with news of NASA’s Parker Solar Probe which has been steadily nearing the sun since 2018. By the time you hear this, there should have been some news of its latest experiences. Experiences which will have taken it 38 times closer to the Sun than we are and into temperatures around 900 degrees Centigrade, while travelling at 430,000 miles per hour.
There are some alternative treats to the more often observed Orion. Thanks to a storytelling session last month hosted by Devon storyteller, Janet Dowling, award-winning author of Folk Tales of the Cosmos, I gained inspiration for this month’s astronomy notes. What is near the mighty Orion…his two hunting dogs of course. So that is what I shall talk about this month. This is not to neglect the annual enjoyment of the Orion nebula, but to explore other observing opportunities out there.
The pair of stars, Sirius A and Sirius B, together make up the brightest star in the northern hemisphere and appear as the main or alpha star in Canis Majoris. The name Sirius is derived from the Greek meaning ‘scorching’. It is one of the nearest stars to us, at a distance of just 8.6 light years away, which is why it appears so bright – it is only twice the mass of the Sun. Sirius B takes 50 years to orbit Sirius A. Representing one of the hunting dogs belonging to Orion, the common name for this star is, unsurprisingly, the Dog Star. Mirzam is the second brightest star in the constellation and the name means
‘herald’. Mirzam precedes Sirius, thus acting as its herald. This blue star is
nowhere near that star though, as it is around 492.5 light years away.
Another bright star in the constellation is even further away, a whopping 1800
light years away. This yellow-white supergiant star, Wezen, is at the tail end of
the dog. It is 17 times as massive as the Sun yet does not appear as bright as
Sirius due to its distance away.
Below Sirius can be found the bright open cluster of stars of M41 which looks as though the stars are arranged in lines.
Canis Minor contains Procyon (one of the marker stars of the Winter Hexagon) but very few other stars, and nothing note-worthy. Procyon, which is comprised of a pair of stars, lies on the celestial equator which makes it a useful guidepost for locating that line. This yellow-white star is 11 light years away and around one and a half times the mass of the Sun.
Once you have located these stars, you will then see Orion striding into view as he follows his two hunting dogs. Orion is a magnificent constellation and to see the distant star forming region of the nebula with the naked eye, albeit faintly, is a sight worth seeing time after time.
Taurus and Auriga are a couple of other constellations you may wish to observe for a change. Taurus contains the bright red ‘eye of the bull’ star Aldebaran, just in front of the pretty Hyades cluster. The Hyades are 150 light years away, with Aldebaran much closer to us at half that distance. It is an old red giant of a star, at 6.5 billion years old, while our Sun is a mere 4.6 billion years old.
The Pleiades, commonly known as the Seven Sisters, although somewhat inevitably there are a quite a few more than 7 … around 750 stars comprise this group can be found to the right of the Hyades. This is one of the brightest and youngest star clusters in the sky, having formed around 100 million years ago, about 444 light years from Earth. From side to side the group spans 13 light years, or about halfway from Earth to the bright star of Vega. Behaving rather like a school of fish, the stars move together as a gravitationally bound swarm through space. It is easy to spot with the naked eye and a lovely object to view through binoculars or a telescope. The more you look, the more you will see.
The star, Alnath, at the tip of one the ‘horns’ of the bull, is shared with the constellation Auriga. The name is derived from the Arabic for ‘butting’. It is the second brightest star in Taurus and is 134 light years away, and obviously helpful for locating this other constellation.
Auriga contains Capella, which, as one of the early stars to be seen as dusk falls, is one of the main navigation stars. This star is also part of the Winter Hexagon asterism. Being right overhead during winter, it is an easy star to spot. Capella (alpha Aurigae) is the main star in the Auriga constellation and is the sixth brightest star in sky. It is actually a pair of yellow giant stars which are 42 light years away.
There are some pretty star clusters within Auriga to look for. M36 Open Cluster contains around 60 stars. Visible in binoculars, this is a cluster similar to the Pleiades. The cluster is 14 light years across and 40,000 light years away.
M37 is a rich Open Cluster of about 150 stars, about 4,500 light years away. The cluster is about 20 – 25 light years across.
And, finally, M38 is a scattered Open Cluster of about 100 stars, which is visible in binoculars. It is 3,400 light years away and 25 light years across, similar to M37.
Well, let’s hope for Clear Skies so we can enjoy all these wonderful stars in clusters and on their own during the proper dark nights of the northern hemisphere winter.
Until next time, my best wishes to you all for a happy, healthy, and peaceful 2025.
Karen Hedges January 2025
Karen Hedges 