sharp telescopic image, globular star cluster Omega Centauri
(NGC 5139) is some 15,000 light-years away.
Some 150 light-years in diameter, the cluster is
packed with about 10 million stars
much older than the Sun.
Cen is the largest of 200 or so known
clusters that roam the
halo of our Milky Way galaxy.
Though most star clusters consist of stars with the same age and
composition, the enigmatic Omega Cen exhibits the presence of
stellar populations with a spread of ages and chemical abundances.
Cen may be the remnant core of a small galaxy merging with
the Milky Way.