Great Cluster in Hercules, aka M13
The Great Cluster in the constellation Hercules is one of the sights those with telescopes search for at this time of year. The eye has difficulty picking it out, but – as shown in this telescopic image from Ido at Bareket Observatory – the cluster is actually a vast symmetrical star city. It contains some 300,000 stars.
This object is a globular star cluster, one of our galaxy’s oldest inhabitants. In other words, as our Milky Way galaxy was forming, globular star clusters are thought to have been among the first things to form.