VISTA Telescope Views a Vast Ball of Stars
Posted on May 10, 2012
The European Southern Observatory's (ESO) VISTA infrared survey telescope has revealed a new image of Messier 55 that shows tens of thousands of stars crowded together like a swarm of bees. These stars are also among the oldest in the universe.
Messier 55, and other ancient objects like it, are called globular clusters. Globular clusters are held together in a tight spherical shape by gravity. In Messier 55, approximately one hundred thousand stars are packed within a sphere with a diameter of only about 25 times the distance between the Sun and the nearest star system, Alpha Centauri. You can view a larger version of the image here.
The French astronomer Nicolas Louis de Lacaille first documented the stellar grouping around 1752, and 26 years later French astronomer, Charles Messier, included the cluster as the 55th entry in his astronomical catalogue.