The brightest globular cluster in the sky, of apparent magnitude 3.7 and width 0°.6, in Centaurus. It is also known as NGC 5139. Omega Centauri is markedly elliptical in shape, with a short axis only 80% the length of its long axis. Its actual diameter is about 180 l.y., and it is the most luminous globular known, with an absolute magnitude of −10.3. At a distance of 17 000 l.y., it is one of the closest globulars to us.
Subjects: Astronomy and Astrophysics.