NGC 1275, one of the most luminous objects in the local universe, is the central galaxy of the Perseus Cluster of galaxies, which is located about 250 million light years from Earth. Only a small part of the galaxy is covered by this image. The bright white spot is the nucleus or center of NGC 1275. The blue dots are bright, dense concentrations of stars, possibly young globular star clusters, If so, each of these little dots is actually a densely packed collection of hundreds of thousands or more stars, like 47 Tucanae and M15 in our own Galaxy. However, the stars in them would be much younger than those in gloublar clusters of the Milky Way. Globular star clusters are among the oldest objects in the Milky Way, and are composed exclusively of very old stars.
NGC 1275, the central and largest galaxy in the Perseus Cluster, has probably merged with several smaller galaxies. When galaxies merge or make close passes, few if any of their billions of stars actually smash into each other because the spaces between the stars are just too wide. But gravitational forces can wreak havoc on the shape of galaxies, and gas clouds, which are much larger than stars, do collide. Theorists suggest that in the case of NGC 1275, the merger process may have triggered the collapse of massive interstellar gas clouds to form the objects identified as young globular clusters.
Camera: WFPC2
Credit: J. Holtzman (UCSC), and NASA
