NGC 3228
| NGC 3228 | |
|---|---|
| Observation data (J2000 epoch) | |
| Constellation | Vela |
| Right ascension | 10h 21m 22s[1] |
| Declination | −51° 43′ 42″[1] |
| Distance | 1,870 ly (573 pc[2]) |
| Apparent magnitude (V) | 6.0 [1] |
| Apparent dimensions (V) | 11'[2] |
| Physical characteristics | |
| Estimated age | 260 million years[2] |
| Other designations | vdBH 93 |
NGC 3228 is an open cluster in Vela. It was discovered by Nicolas Louis de Lacaille in 1751-1752, while he was in South Africa and catalogued it as Lac II.7.[3] It is small but bright and can be observed easily with binoculars in sufficiently dark skies.[4]
It is a cluster of Trumpler type I1p or II3p, with few members with large brightness range and a slight concentration toward its center.[3] Klarchenko et al. mention 53 possible members within the angular diametre of the cluster. The tidal radius of the cluster is 1.4 - 5.5 parsecs (4.5 - 18 light years) and represents the average outer limit of NGC 3228, beyond which a star is unlikely to remain gravitationally bound to the cluster core.[2] The brightest member is of mag. 7.9 and the hottest star is of spectral type B9.[3] One member, HD 89856 (mag. 9.04, spectral type B9), is a variable star with period 4.556 days.[5]
References
- ↑ 1.0 1.1 1.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
- NGC 3228 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
