M13 Globular

M13 Globular Cluster in Hercules

This globular cluster is 25100 light years away. It contains more than 100,000 stars yet it's diameter is just 145 light years. It is more than 12 billion years old. The cluster has an apparent magnitude of 5.8, but the brightest star within the cluster (variable star V11) has a magnitude of just 11.95

In this image East is up and North is to the right. The spiral galaxy at the top right of the image (15 arc minutes NNE of M13) is IC 4617, magnitude 15.2. This galaxy is a very challenging object to see visually.

For more information, try: www.seds.org/messier/m/m013.html