Nightscapes & Deep Sky Colors
Astrophotography © Brian A. Morganti
M13 - Globular Cluster
The Great Globular Cluster
M13 is one of the largest and most impressive globular star clusters visible from the northern hemisphere. The cluster is about 25,000 light years from Earth, and contains several hundred thousand stars. M13 covers about 20 arc minutes in the sky, which makes it about 2/3 the size of a full moon. This corresponds to a real size of about 145 light-years and it contains hundreds of thousands of stars. At magnitude 5.8, M13 is visible to the keen unaided eye from a dark-sky observing site.
Galaxy NGC 6207 can be seen at the lower left. M13 was discovered in 1714 by Edmond Halley and catalogued by Charles Messier in 1764.
North is to the left in the above image.
Astrophotography - Nightscapes & Deep Sky Colors