Stunning Hubble Image Reveals Dazzling Messier 55 Star Cluster.
The Hubble Space Telescope has captured a new image of Messier 55, a loosely concentrated globular star cluster located about 20,000 light-years away. The cluster appears spherical due to the intense gravitational attraction between its stars. While ground-based telescopes can also resolve individual stars in M55, Hubble's clear view above Earth's atmosphere allows for a better resolution. The cluster contains an estimated 100,000 stars with 55 variable stars, and is found in the southern part of the constellation Sagittarius.