Comments:
It was discovered by Jean-Dominique Maraldi in 1746. Situated in Pegasus, it is about 30 thousand light years away. Globular clusters move round the Galaxy in elliptical orbits. M15 is currently approaching us with a speed of 107 km/h.

It's a very interesting cluster for several reasons:

It contains many variable stars.

It is the first globular cluster that was discovered to have a planetary nebula in it.

It contains nine (!) pulsars.

The central core of the cluster seems to be collapsing under its own gravity. This is a natural part of a cluster’s life and helps the cluster remain intact.