Globular Cluster M 5

Globular cluster M5 in the constellation Serpens. Spanning 165 light-years in diameter, M5 is one of the largest known globular star clusters. The sphere of gravitational influence of M5—that is, the volume of space where stars would be gravitationally bound to the cluster rather than being pulled away by the Milky Way’s gravity—has a radius of about 200 light-years. This large cluster is among the most massive in the vicinity of our Galaxy, with a mass equivalent to 2 million solar masses.

At an age of 13 billion years, this cluster is also one of the oldest in the Milky Way Galaxy. The distance from Earth to M5 is about 24,500 light-years. The cluster contains, by various estimates, between 100,000 and 500,000 stars.