BLACK DOG OBSERVATORY

NGC4139 Omega Centauri

This Globular is the largest and most luminous Globular Cluster in the Milky Way and is said by some to be the finest of all. It has around 1,000,000 stars and at 17,000 light years away, it's the second closest after NGC6397 Globular in Ara. Its shape is more oval than round and its mass is 5,000,000 times that of our Sun. It is about 10 times more massive than a typical large Globular and is as massive as the smallest of whole galaxies. It is outshone only by the Andromeda Galaxy. The stars within the cluster formed over a 2 billion year period. It may be that it is the remnant of a small galaxy that merged with the Milky Way.