Palomar 12
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Globular cluster Palomar 12 |
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| Image taken with the Hubble Space Telescope | |
| AladinLite | |
| Constellation | Capricorn |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 21 h 46 m 39 s |
| declination | -21 ° 15 ′ 03 ″ |
| Appearance | |
| Concentration class | XII |
| Brightness (visual) | 12 likes |
| Angular expansion | 17.4 ' |
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Color excess E (BV) (redness) |
0.02 mag |
| Physical data | |
| Affiliation | Milky Way |
| Radial velocity | +27.8 ± 1.5 km / s |
| distance | 62.3 kLj |
| Absolute brightness | −4.48 mag |
| Core radius | 37.8 "± 0.6" |
| Concentration lg (r t / r c ) | 1.08 ± 0.02 |
| Age | 9 ± 1 billion years |
| Metallicity [Fe / H] | −0.94 |
| history | |
| Catalog names | |
| C 2143-214 • GCl 123 • ESO 600-SC 011 • Pal 12; UGCA 421; MCG- 04-51-013 | |
Palomar 12 (short: Pal 12 ) is a globular cluster at a distance of around 62,000 light years in the constellation Capricorn . The object was discovered in 1953 by Robert G. Harrington and Fritz Zwicky .
After Pal 12 was classified as a globular cluster, Zwicky later classified Pal 12 as a dwarf galaxy in the local group , giving it the name Capricornus dwarf galaxy . However, later observations confirmed the initial classification.
Since the stars in Palomar 12 are almost a third younger than usual in galactic globular clusters, it is assumed that Pal 12 originally belonged to the Sagittarius dwarf galaxy , but was captured by the Milky Way during a close encounter.