M13 The Great Cluster

Without doubt the finest of globular clusters visible in the northern hemisphere. Located outside the plane of our galaxy and some 25,000 light years away.

An easy target to find.

M13 is located in the constellation Hercules, between summertime’s two brightest stars, Vega and Arcturus. About 1/3 of the way from Vega to Arcturus, locate the four modestly bright stars forming the Keystone of Hercules. On the Arcturus side of the Keystone, M13 lies between the stars Eta Herculis and Zeta Herculis.

A typical binocular field is about 5 to 7 degrees in diameter, and the Hercules cluster is found about 2.5 degrees south of Eta Herculis. The Hercules cluster’s position is Right Ascension: 16h 41.7m; Declination: 36 degrees 28′ north.

M13 was one of my first targets I captured many years ago. The cluster will not have changed since it's discovery over 300 years ago,  but my imaging and processing have. This Image is just 1.5 hours of data using the ZWO RGB filters, 30 minutes per filter.

Cropped image

Processed in Pixinsight.