Hubble peers at core of globular cluster

This Hubble picture shows a dense swarm of stars called Omega Centauri.

By Amanda Barnett
CNN

(CNN) -- NASA's Hubble Space Telescope has allowed astronomers to peek into the center of a cluster of stars so densely packed that the stars occasionally collide.

Called Omega Centauri, the cluster is located about 17,000 light-years from Earth. It contains several million stars swirling in locked orbits around a common center of gravity.

The star cluster is so congested that astronomers using ground-based telescopes have a hard time picking out individual stars. Hubble's high resolution is able to separate out distinct points of light from the stars.

This Hubble image was taken on June 11, 1997. Most of the stars in the picture are faint, yellow-white dwarf stars similar to our Sun. The image also shows a few bright yellow-orange stars. These are red giants that have started to run out of fuel. The picture also shows faint blue stars -- stars between the dwarf and red-giant stages.

Omega Centauri is the most luminous and massive globular star cluster in the Milky Way. The stars in the cluster are about 12 billion years old.

Omega Centauri is one of the few globular clusters that can be seen with the unaided eye. It looks like a small cloud in the southern sky.