M5

M5 is a class V globular cluster of the Milky Way. Slightly elliptical in appearance, M5 is believed to be one of the oldest globular clusters with a calculated age of 13 billion years, and it contains 104 known variable stars - as well as a dwarf nova. Stretching 165 light-years of space, the magnificent object so dominates its territory that it would gather in any stars straying within 400 light-years of its tidal influence.

The cluster is also known as NGC 5904.