M13

M13 (also NGC 6205), is a globular cluster, in the Hercules constellation at Right ascension 16^h 41.7^m and Declination +36° 28'

M13 in Hercules is one of the most prominent and best known globular clusters of the Northern celestial hemisphere

With an apparent magnitude of 5.8, it is barely visible with the naked eye on a very clear night. Its real diameter is about 165 light years, and is composed of several 100,000 stars.

See also:

Messier 13, SEDS Messier pages