The image of the globular star cluster Messier 55 in the constellation of Sagittarius was captured with the VISTA survey telescope at the European Southern Observatory's Paranal facility, a release from ESO headquarters in Munich, Germany, said Wednesday.
About 100,000 stars in the cluster 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, astronomers said.
Messier 55 is one of about 160 globular clusters that have been spotted in the Milky Way galaxy, mostly toward its bulging center.
Analysis of infrared images of the globular clusters' stars reveal they originated around the same time -- more than 10 billion years ago -- just a few billion years after the big bang.
The sun, in contrast, lit up around 4.6 billion years ago, making it only about half as old as the elderly stars in most globular clusters, astronomers said.