Higher-resolution versions:  1280 x 1024  2140 x 1386

Object Type: Globular cluster
Constellation: Centaurus
Magnitude: 3.7
Size: 36'

Also known as Omega Centauri, NGC 5139 is the largest and brightest globular cluster associated with the Milky Way galaxy. It has an estimated mass of 5 million solar masses, many times that of other large globular clusters such as M13 which has about 600,000 solar masses. Unlike other globular clusters, NGC 5139 has several different populations of stars which formed at different times over a 2 billion year period, which suggests that it may be the remnant core of a galaxy which merged with the Milky Way.

Equipment: Vixen 102-ED/ST-10XME/Astrodon RGB filters/Losmandy G-11/Gemini
F-ratio: f/6.5
Exposures: LRGB:  10 x 6 minutes: R 10 x 6 minutes: G 10 x 6 minutes: B 11 x 6 minutes: RGB binned 2x2
Date: April 20, 21, and 23, 2009
Location: Fort Davis, Texas, USA (Texas Star Party)