This week it’s time to track down a large but easily overlooked constellation. Boötes, the herdsman, is an ancient constellation that was catalogued by the Greek astronomer Ptolemy in the second century. References to the stars in this constellation date back even further, however, to the ancient Babylonians, where they represented the god Enil, the patron of farming.
The easiest way to find Boötes is to find the orange star, Arcturus. This is the brightest star in the northern celestial hemisphere, and the third brightest star in the entire night sky. It is outshone only by Sirius and Canopus, both of which are located in the southern celestial hemisphere.
The chart shows the view on Monday night looking due south at 23:00 BST. Throughout the week, the view will be similar.
Boötes is flanked by Hercules, the hero, to the east and Virgo, the virgin, to the south. If you can recognise the Plough, which will be even higher in the sky, follow the curve of the stars in its handle downwards and you will arrive at Arcturus, then use the chart to trace out the fainter stars of Boötes.
For observers in the southern hemisphere, Arcturus and Boötes can seen in the northern sky during the winter months.