Arches Cluster: Hubble/NICMOS (1997)

This ESO/NASA Hubble Space Telescope picture presents the Arches Cluster, the densest known star cluster in the Milky Way. It is located about 25 000 light years from Earth in the constellation of Sagittarius. The radius of the cluster is only about one light year, but it contains about 150 stars, all of which are larger and more massive than the Sun.