Globular Cluster

From Slackerpedia Galactica

A gravitationally self-bound cluster of co-eval stars. Globular clusters contain thousands of stars, all of which formed at the same time from (presumably) a large-but-not-galaxy-sized primordial gas cloud. Globular clusters in the Milky Way are old, and probably formed early on in the galaxy's history. But globular clusters may still be forming, in galaxies with active star formation, or that are in the midst of mergers with other galaxies.

Globular clusters are important laboratories for astrophysics. Because the stars are co-eval, you can study stellar evolution in a single, well-defined population of stars. Globular clusters played a role in the development of cosmology and the structure of the universe. The distribution of globular clusters in our sky -- noticeably skewed towards the bulge of the Milky Way -- provided a vital clue about Earth's position in the Galaxy. Pulsating variable stars in globular clusters provided important standard candles for the measurement of cosmic distance scales.

They also make pretty photo subjects.