September skies – the autumn equinox and the dog days of summer

September approaches and with it the autumn equinox and the dog days of summer. Nights overtake the days and we move into autumn. In the evenings the planets still put on a good show with Mars, Jupiter and Saturn all easily visible albeit low on the Southern horizon. Higher in the sky deep sky objects make a nice challenge for people who are starting to use telescopes. One of the nicest is the Ring Nebula. Almost directly overhead in the evening skies of late summer is the bright star Vega in the constellation of Lyra. South of Vega are two brightish stars at the base of the constellation and almost directly between them lies a planetary nebula which is a glimpse of how a star like our Sun will die. In the last phases of its life the Sun will swell up and send wisps of its outer layers into space to make some of the most beautiful objects in the universe.

The dog days of summer is a strange phrase with origins in the stars. Those of us who are early risers may see the constellation Orion in the skies before dawn. Orion is portrayed in legend as a hunter and in this guise he is closely by his dogs, Canis Major and Canis Minor. Those constellations are dominated by two bright stars Sirius in the great dog and Procyon in the small dog. For a short while at this time of year those stars are briefly visible in the morning sky before the Sun rises and from that we get the phrase the “dog days of summer”.

The Parker Solar Probe image courtesy of NASA

A short way behind Orion and his dogs follows Leo and that is where we find the Sun at the moment in the constellation of Leo. If anyone knows the traditional zodiac dates they will realise that those signs are wrong. Just as the Earth moves to give us seasons it also moves the constellations around the year. Wind the clock back four thousand years to the time of the ancient Egyptians and the zodiac lines up with the real constellations and the rising of Sirius would mark the start of the ancient Egyptian year.

Back in the present day, science rather than myth turns its eyes to our star. Last month the Parker Solar Probe launched on its seven year path to reach and study the Sun. It will approach within 6 million km from the Sun and as it does will become the fastest spaceship we have ever created and encounter some of the most extreme conditions yet experienced. In so doing it should improve our understanding of solar conditions and storms that threaten spacecraft and technology nearer to and on the Earth.

Much nearer the Observatory Science Centre starts September with our annual astronomy festival. For the weekend of the 1st and 2nd of September the site is turned over to our 14th festival with a program of speakers, planetarium shows, trade stands societies, the occasional attack from Stormtroopers and more. In the nights amateurs camping will continue with their observations and if the weather cooperates the observatory’s telescopes will be opened in the evening for the public to use and we should be able to turn them to the objects of the evening sky such as the ring nebula.

The Observatory Science Centre will be open every day throughout August and September with the exception of Monday 3rd September. It will also be open on the evening of the 22nd September and in the evenings of 31st August – 1st September for our annual astronomy festival.

Thanks to Jarvis Brand for this article. He runs the planetarium for the Observatory Science Centre and can be contacted on planetarium@the-observatory.org or on 01323 832 731.