Constellation of the Month: Hercules
The month of June has the shortest nights of the year (for northern hemisphere stargazers), but there’s still plenty to see if you wait till the sky gets dark after midnight.
Sitting high in the south – almost directly overhead – during June is the constellation of Hercules.
The body of Hercules is made up of four stars in an asterism known as The Keystone. The four stars in The Keystone, like all the star in Hercules, are not especially bright, so the pattern doesn’t stand out all that clearly. To find it draw a line from the bright orange star Arcturus to the bright white star Vega. Hercules sits about 2/3 of the way along this line.
Once you find the Keystone try and trace the four lines that come off each corner, Hercules’s arms and legs.
But the most interesting feature in Hercules is the faint fuzzy patch known as the Great Globular Cluster in Hercules, M13 (marked with a + above).
M13 lies on a line drawn between two of the stars of the Keystone, ζ and η Her. It’s just visible to the naked eye in dark sky conditions (which you won’t get during the summer months) but is easily found using binoculars. It will look like a fuzzy out-of-focus star.
In fact it is a globular (globe-shape) cluster of around 300,000 very old stars, orbiting our galaxy.
If you’ve got a powerful telescope then you should be able to make out individual stars within this cluster.