Upsilon Carinae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | 09h 47m 06.12170s |
| Declination | −65° 04′ 19.2267″ |
| Apparent magnitude (V) | 2.97 (+3.08/+6.25) |
| Characteristics | |
| Spectral type | A8 Ib + B7 III |
| U−B color index | +0.13 |
| B−V color index | +0.27 |
| Astrometry | |
| Radial velocity (Rv) | +13.6±0.5 km/s |
| Proper motion (μ) | RA: −11.51 mas/yr Dec.: +4.71 mas/yr |
| Parallax (π) | 2.27±0.28 mas |
| Distance | approx. 1,400 ly (approx. 440 pc) |
| Absolute magnitude (MV) | −5.26 |
| Details | |
| υ Car A | |
| Mass | 10.88 M☉ |
| Radius | 96.6 – 100 R☉ |
| Surface gravity (log g) | 1.4±0.1 cgs |
| Temperature | 7,500±100 K |
| Age | 23.4 Myr |
| υ Car B | |
| Mass | 8 M☉ |
| Surface gravity (log g) | 3.3±0.1 cgs |
| Temperature | 23,000±1,600 K |
| Other designations | |
| υ Car, CPD−64°1084, GC 13506, HIP 48002, WDS J09471-6504 | |
| A: HD 85124, HR 3890, SAO 250696 | |
| B: HD 85123, HR 3891, SAO 250695 | |
| Database references | |
| SIMBAD | system |
| A | |
| B | |
Upsilon Carinae is a double star in the southern constellation of Carina. Its name is a Bayer designation that is Latinized from υ Carinae, and abbreviated Upsilon Car or υ Car. This pair is part of the Diamond Cross asterism in southern Carina. The Upsilon Carinae system has a combined apparent magnitude of +2.97 and is approximately 1,400 light years (440 parsecs) from Earth. It is drifting further away with a line of sight velocity of +14 km/s.
In Chinese, 海石 (Hǎi Dàn), meaning Sea Rock, refers to an asterism consisting of υ Carinae, ε Carinae, ι Carinae, HD 83183 and HD 84810. Consequently, υ Carinae itself is known as 海石五 (Hǎi Dàn wǔ, English: the Fifth Star of Sea Rock.)
In the next 7500 years, the south Celestial pole will pass close to these stars and Iota Carinae (8100 CE).