What is left over after stars collide? To help answer this question, astronomers have been studying the center of the most massive ball of stars in our Milky Way Galaxy . In the center of globular cluster Omega Centauri, stars are packed in 10,000 times more densely than near our Sun. Pictured above , the Hubble Space Telescope has resolved the very center of Omega Centauri into individual stars. Visible are many faint yellow-white stars that are smaller than our Sun , several yellow-orange stars that are Red Giants , and an occasional blue star . When two stars collide they likely either combine to form one more massive star, or they stick, forming a new binary star system. Close binary stars interact, sometimes emitting ultraviolet or X-ray light when gas falls from one star onto the surface of a compact companion such as a white dwarf or neutron star . Two such binaries have now been located in Omega Centauri 's center. The star cluster lies about 15,000 light-years away and is visible toward the constellation of Centaurus .
10 October 2001
The Center of Globular Cluster Omega Centauri
