The better weather has provided more chances of viewing the night sky but my attempts to catch Mercury at the end of April just after sunset were thwarted by hazy clouds on my western horizon. Also, on the 24th April, the weather wasn’t favourable for seeing the pre-dawn planetary alignment.
Okay, it is time to look at the stars. The following charts represent the night sky at 10.00pm BST on the 8th of May and at 9.00pm BST on the 23rd May.
We looked at The Plough last month and we’ll start there this month as it is such a good signpost for finding our way about the night sky. You will find the middle of the handle near your zenith (directly above you) so, facing south, follow the arc of the handle of The Plough downwards to the brightest star in that region, Arcturus, which has the distinction of being the second brightest star visible in the northern hemisphere at a magnitude of about 0.2. It is an orange giant nearing the end of its life and is relatively close at 36 light years. It is the brightest star in the constellation Bootes- The Herdsman but it is difficult to distinguish such a figure whereas the Kite asterism is easy to see and is what most people recognise as Bootes.
Also marked on the chart is the second brightest star in Bootes, Izar, a binary star consisting of an orange giant and a blue star, well worth a look through a telescope if you get the chance.
In the second chart you should immediately recognise the constellation Leo- The Lion which we looked at in March. Between Bootes and Leo lies the constellation Coma Berenices supposedly representing the hair of Queen Berenice of Egypt but it contains no stars brighter than magnitude 4.
Carry on following the arc from Arcturus for about the same distance again until you see another bright star. This is Spica the brightest star in the constellation Virgo- The Maiden, which is one of the zodiacal constellations. Spica is a blue-white star with an average magnitude of about 1 and is 260 light years from Earth. It may be easier to memorise these two star hops using the expression (Arc on to Arcturus and Speed on to Spica).
Something to look out for
As previously mentioned the planets are not favourably positioned for viewing at present so I am repeating the orbital diagram I showed in February. You can see that the planets Venus, Mars, Jupiter and Saturn are visible only in the morning and not visible at all during the evening or nightime. At present, as the Earth rotates on its axis, these planets are positioned such that they rise in the east just before the Sun which proceeds to outshine them when it rises. Now the outer planets orbit more slowly than the Earth and have further to travel during an orbit ( Jupiter takes about thirty Earth years to complete its orbit) so what has to happen is that the faster travelling Earth must overtake them and position itself between them and the Sun and once again they will appear in our night sky in a few months.
You can still look out for Mercury to the West just after sunset. Otherwise enjoy the Moon and the constellations.