Star City

A new survey of the Milky Way galaxy has discovered two previously undetected "cities" of stars known as globular clusters, which are dense collections of hundreds of thousands of stars. One of the two is inside the yellow circle in this image, from the European Southern Observatory in Chile. The new cluster resembles the one at right, which was already known before the survey. Globular clusters reside in the galaxy's halo, which extends far beyond the Milky Way's broad, flat disk. Their stars are the oldest in the galaxy -- at least 10 billion years old, and some of them much older. All of their hot, bright stars have long since exploded or expelled their outer layers into space, leaving only smaller, cooler, fainter stars. The new discoveries bring the total number of known globulars in the Milky Way to 160. [ESO/D. Minniti/VVV Team]