Object Analysis

Messier 15 (M15) is a globular cluster in the constellation Pegasus. It is one of the oldest known globular clusters, estimated to be 12 billion years old, and one of the most densely packed. It has undergone a process called "core collapse," where the central stars have migrated inward due to gravitational interactions.

M15 is arguably the densest of all globular clusters in the Milky Way galaxy. Its core is so compact that it is suspected to harbor an intermediate-mass black hole roughly 4,000 times the mass of the Sun.

It is also famous for being the first globular cluster known to contain a planetary nebula, Pease 1. This nebula is the ejected outer layer of a dying star within the cluster, appearing as a tiny blue dot among the golden glow of the ancient stars.