Theta Carinae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 42m 57.40197s |
| Declination | −64° 23′ 40.0208″ |
| Apparent magnitude (V) | 2.76 |
| Characteristics | |
| Evolutionary stage | Blue straggler |
| Spectral type | B0.5 Vp |
| U−B color index | −1.00 |
| B−V color index | −0.22 |
| Astrometry | |
| Radial velocity (Rv) | +24 km/s |
| Proper motion (μ) | RA: −18.36 mas/yr Dec.: +12.03 mas/yr |
| Parallax (π) | 7.16±0.21 mas |
| Distance | 460 ± 10 ly (140 ± 4 pc) |
| Absolute magnitude (MV) | −3.10 |
| Orbit | |
| Period (P) | 2.20288±0.00001 d |
| Eccentricity (e) | 0.129±0.002 |
| Argument of periastron (ω) (secondary) | 81.8±1.7° |
| Semi-amplitude (K1) (primary) | 18.93±0.05 km/s |
| Details | |
| θ Car A | |
| Mass | 14.9±0.4 M☉ |
| Radius | 5.1 R☉ |
| Luminosity | 14,500±1,000 L☉ |
| Surface gravity (log g) | 4.20 cgs |
| Temperature | 31,000±1,000 K |
| Rotational velocity (v sin i) | 108±3 km/s |
| Age | 35 - 46 Myr |
| Other designations | |
| θ Car, CPD−63°1599, FK5 406, HD 93030, HIP 52419, HR 4199, SAO 251083. | |
| Database references | |
| SIMBAD | data |
θ Carinae, Latinized as Theta Carinae, is a spectroscopic binary star in the southern constellation of Carina. With an apparent visual magnitude of 2.76, it is the brightest star in the open star cluster IC 2602. It marks the northeastern end of the Diamond Cross asterism. Parallax measurements from the Hipparcos mission place this star at a distance of about 460 light-years (140 parsecs) from Earth.