WR 22
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 41m 17.51590s |
| Declination | −59° 40′ 36.8957″ |
| Apparent magnitude (V) | 6.42 |
| Characteristics | |
| Spectral type | WN7h + O9III-V |
| Apparent magnitude (U) | 5.68 |
| Apparent magnitude (B) | 6.50 |
| Apparent magnitude (J) | 5.705 |
| Apparent magnitude (H) | 5.578 |
| Apparent magnitude (K) | 5.389 |
| U−B color index | −0.82 |
| B−V color index | 0.08 |
| J−H color index | 0.127 |
| J−K color index | 0.316 |
| Variable type | Eclipsing binary |
| Astrometry | |
| Radial velocity (Rv) | −28.00 km/s |
| Proper motion (μ) | RA: −7.321 mas/yr Dec.: 3.091 mas/yr |
| Parallax (π) | 0.3953±0.0348 mas |
| Distance | 8,300 ± 700 ly (2,500 ± 200 pc) |
| Absolute magnitude (MV) | −6.73 + −4.44 |
| Orbit | |
| Primary | WR |
| Companion | O |
| Period (P) | 80.336 days |
| Semi-major axis (a) | 330 R☉ |
| Eccentricity (e) | 0.598 |
| Inclination (i) | 83.5° |
| Argument of periastron (ω) (secondary) | 268.2° |
| Semi-amplitude (K1) (primary) | 70.6 km/s |
| Semi-amplitude (K2) (secondary) | 190.0 km/s |
| Details | |
| WR | |
| Mass | 49 - 75 M☉ |
| Radius | 22.65 R☉ |
| Luminosity | 1,905,000 L☉ |
| Temperature | 44,700 K |
| O | |
| Mass | 25.7 M☉ |
| Radius | 11 R☉ |
| Luminosity | 130,000 L☉ |
| Temperature | 33,000 K |
| Age | 2.2 Myr |
| Other designations | |
| CD−59°3221, HR 4188, HD 92740, V429 Carinae, HIP 52308 | |
| Database references | |
| SIMBAD | data |
WR 22, also known as V429 Carinae or HR 4188, is an eclipsing binary star system in the constellation Carina. The system contains a Wolf-Rayet (WR) star that is one of the most massive and most luminous stars known, and is also a bright X-ray source due to colliding winds with a less massive O class companion. Its eclipsing nature and apparent magnitude make it very useful for constraining the properties of luminous hydrogen-rich WR stars.
In 1978, Anthony Moffat and Wilhelm Seggewiss announced that the star's brightness varies. Eclipses were first detected by Luis A. Balona et al. in 1989. It received its variable star designation, V429 Carinae, in 1980.