Fortunately we have had the benefit of a few clear skies and so have had a chance to see a bit more of the winter sky. Mars continues to provide good viewing even though it is waning in magnitude and it was good to see its close lunar approach in the middle of the month. On the 28th February the Moon was close to Regulus in the constellation Leo- The Lion, but if you watched Ben Sutlieff’s excellent talk on ‘imaging exoplanets’ and his use of a coronagraph you will understand something similar was needed to block out the light from the full Moon. I settled for observing with one eye and using my thumb at arms length to block out the Moon!
The chart below represents the south facing night sky at 9.00pm GMT on the 8th March and at 8.00pm GMT on the 23rd March. Remember it is the spring equinox on Saturday 20th March and we move to BST on Sunday 28th March.
This month we are focussing on just one constellation, Leo- The Lion. The chart includes the stars Castor and Pollux in Gemini and the star Procyon in Canis Minor just to give us our bearings. The chart also includes the faint stars in the constellation Cancer- The Crab and part of the constellation Hydra- The Water Snake but we discussed those last month and they are difficult to see.
Having located the two main stars in Gemini and the star Procyon you need to turn towards the south-east and you will have no trouble in picking out Leo. I think it deserves its name because I can imagine the outline of a lion in a crouching position.The main star is Regulus, the 15th brightest star in the northern hemisphere at magnitude 1.4. Above Regulus is the asterism- The Sickle, which I have outlined in red. The other three stars in Leo which I have named are perhaps not well known but Denebola, Algieba and Zosma have magnitudes of 2.1, 2.2 and 2.6 respectively which explains why Leo stands out so well. Leo is towards the east just now so you will be able to enjoy observing it as it travels westwards over the coming months. Let’s hope we have plenty of clear skies.
Something to look out for
I mentioned Mars in the introduction and am returning to it again because at the beginning of March it passes close to the Pleiades open cluster and on the 3rd/4th March passes within 2.5 degrees of same. Not as eyecatching as Venus when it did something similar last Spring but well worth observing never-the-less. Throuhout the month it travels eastwards through the constellation Taurus, passing north of the red giant star Aldebaran about the middle of the month.We had difficulty tracking its retrograde motion last Autumn because there were no bright stars nearby but this time you can track its movement relative to Aldebaran.It also has a close approach to a six day old Moon on the 19th March so you will see Mars, the Moon and Aldebaran all together.
Last month I mentioned the open cluster, Praesepe, (marked on the chart with a red cross and also known as ‘the Beehive’) as a difficult target for observation and perhaps with better conditions it will be possible in March.
Finally with the Spring Equinox on the 20th March we’ll have another chance to to fix directions because on that date the Sun rises due East and sets due West. There is a housing estate being built close to where I live and I’m hoping I don’t have the roof of a house blocking out my horizon to the West!
Good luck with your observing!