Messier 13 (M13), also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of about 300,000 stars in the constellation of Hercules.
M13 was discovered by Edmond Halley in 1714, and catalogued by Charles Messier on June 1, 1764 (Wikipedia).
LRGB composition, total integration 1.7hrs, May 2014. William Optics FLT132 at F5.6 - Avalon Linear Fast Reverse - Atik 460EX - Baader LRGB Filters.
M13Great Globular ClusterHercules