  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 11h 31m 48.79955s[1] |
| Declination | −59° 30′ 56.3296″[1] |
| Apparent magnitude (V) | +5.14[2] (5.12 - 5.22[3]) |
| Characteristics | |
| Spectral type | A2Iae[3] |
| U−B color index | −0.11[2] |
| B−V color index | +0.49[2] |
| Variable type | α Cyg[3] |
| Astrometry | |
| Radial velocity (Rv) | −16.8[4] km/s |
| Proper motion (μ) | RA: −6.976[1] mas/yr Dec.: +1.118[1] mas/yr |
| Parallax (π) | 0.4665 ± 0.0713 mas[1] |
| Distance | approx. 7,000 ly (approx. 2,100 pc) |
| Absolute magnitude (MV) | −7.50[5] |
| Details[5] | |
| Mass | 18 M☉ |
| Radius | 131 R☉ |
| Luminosity | 105,000 L☉ |
| Surface gravity (log g) | 1.46 cgs |
| Temperature | 9,080 K |
| Rotation | 132 days |
| Rotational velocity (v sin i) | 50 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Omicron2 Centauri (ο2 Cen, ο2 Centauri) is a star in the constellation Centaurus.
ο2 Centauri is a white A-type supergiant with a mean apparent magnitude of +5.12. It is approximately 7,000 light years from Earth. It is classified as an Alpha Cygni type variable star and its brightness varies from magnitude +5.12 to +5.22 with a period of 46.3 days.
In 1996, Kaufer and colleagues calculated Omicron2 Centauri to be around 136,000 times as luminous, 18 times as massive and have 131 times the diameter of the Sun.[5]
ο2 Cen forms a close naked eye pair with ο1 Cen, another 5th magnitude supergiant.
