Omega Centauri
Globular cluster ω Centauri |
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Image taken using VST , image field 51 'x 51'. | |
AladinLite | |
Constellation | centaur |
Position equinox : J2000.0 , epoch : J2000.0 |
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Right ascension | 13 h 26 m 45.9 s |
declination | −47 ° 28 ′ 37 ″ |
Appearance | |
Concentration class | VIII |
Brightness (visual) | 5.3 mag |
Brightness (B-band) | 6.1 mag |
Angular expansion | 55 ′ |
Physical data | |
Affiliation | Milky Way |
Redshift | (794 ± 17) · 10 −6 |
Radial velocity | (+238 ± 5) km / s |
distance | 17.3 kLj (5.3 kpc ) |
diameter | approx. 150 ly |
Age | approx. 12 billion years |
history | |
discovery | Edmond Halley |
Discovery date | 1677 |
Catalog names | |
NGC 5139 • C 1323-472 • GCl 24 • ESO 270-SC11 • Dun 440 • GC 3531 • |
ω Centauri ( Omega Centauri, ω Cen for short , also known as NGC 5139) is a globular cluster in the constellation Centaur . It has an apparent diameter of 55 ′ and an apparent magnitude of 5.3 mag. This makes it the brightest globular cluster in the sky and visible as a small nebula with the naked eye. It also has the greatest absolute brightness , as it is by far the most massive globular star cluster in our Milky Way . Within the Local Group , it is only surpassed in size by Mayall II , a globular cluster of the Andromeda Galaxy. Omega Centauri contains around 10 million stars.
Research history
Although ω Centauri is not a star, it was given a Bayer designation . The object differs from other globular clusters in that it contains several star populations . The latest research carried out with the Hubble Space Telescope and the Gemini Observatory shows that ω Centauri is probably a dwarf galaxy that has since been robbed of its stars by the Milky Way . The peculiarity of this object will now be easier to explain since a black hole with 40,000 solar masses has been found in the center.
High-resolution image of the center using the Hubble space telescope
Infrared image from the Spitzer Space Telescope
Web links
- Hubble Space Telescope
- Spitzer space telescope
- Cosmic record holder - video on Spiegel-Online
- NGC5139 on astro-pics
literature
- Floor van Leeuwen, Joanne D. Hughes, Giampaolo Piotto (Eds.): Omega Centauri, A Unique Window into Astrophysics . 2002, ISBN 1-58381-105-2 , bibcode : 2002ASPC..265 ..... V .
Individual evidence
- ^ NED
- ↑ a b c d SEDS: NGC 5139
- ↑ SIMBAD database
- ↑ a b Astronomers Find Suspected Medium-Size Black Hole in Omega Centauri. April 2, 2008.
- ↑ a b Article on Spiegel-Online
- ↑ Seligman
- ↑ heic0809 - Science Release: Black hole found in enigmatic Omega Centauri. April 2, 2008.