WR 30a
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 51m 38.906s |
| Declination | −60° 56′ 34.91″ |
| Apparent magnitude (V) | 12.73 |
| Characteristics | |
| Evolutionary stage | Wolf–Rayet star |
| Spectral type | WO4 + O5((f)) |
| U−B color index | −0.22 |
| B−V color index | +1.04 |
| Variable type | WR |
| Astrometry | |
| Proper motion (μ) | RA: −5.642 mas/yr Dec.: 2.842 mas/yr |
| Parallax (π) | 0.1201±0.0099 mas |
| Distance | 6,720+1,400 −1,090 pc |
| Absolute magnitude (MV) | −5.39 (−2.80 + −5.38) |
| Orbit | |
| Primary | WR |
| Companion | O |
| Period (P) | 4.619 days |
| Semi-major axis (a) | 35.4 R☉ |
| Eccentricity (e) | 0.2 |
| Inclination (i) | 20 ± 5° |
| Semi-amplitude (K1) (primary) | 189 km/s |
| Semi-amplitude (K2) (secondary) | 25 km/s |
| Details | |
| WR | |
| Mass | 7.5-9.7 M☉ |
| Radius | 0.88 R☉ |
| Luminosity | 195,000 L☉ |
| Temperature | 129,500 K |
| O | |
| Mass | 40-60 M☉ |
| Other designations | |
| WR 29a, V574 Carinae, GSC 08958-04143, MS4 | |
| Database references | |
| SIMBAD | data |
WR 30a is a massive spectroscopic binary in the Milky Way galaxy, in the constellation Carina. The primary is an extremely rare star on the WO oxygen sequence and the secondary a massive class O star. It appears near the Carina Nebula but is much further away.