W Orionis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 05m 23.72142s |
| Declination | +01° 10′ 39.4512″ |
| Apparent magnitude (V) | 4.4 - 6.9 |
| Characteristics | |
| Evolutionary stage | AGB |
| Spectral type | C-N5 C25.5 (C5,4(N5)) |
| U−B color index | +6.84 |
| B−V color index | +3.42 |
| Variable type | SRb |
| Astrometry | |
| Radial velocity (Rv) | +16.50 km/s |
| Proper motion (μ) | RA: +7.5 mas/yr Dec.: -1.4 mas/yr |
| Parallax (π) | 2.65±0.95 mas |
| Distance | approx. 1,200 ly (approx. 400 pc) |
| Absolute magnitude (MV) | −5.76 |
| Details | |
| Mass | 1-2 M☉ |
| Radius | 406 R☉ |
| Luminosity | 6,761 L☉ |
| Surface gravity (log g) | −0.60 cgs |
| Temperature | 2,600 K |
| Metallicity [Fe/H] | 0.0 dex |
| Other designations | |
| W Ori, BD+00°939, HD 32736, HIP 23680 | |
| Database references | |
| SIMBAD | data |
W Orionis is a carbon star in the constellation Orion, approximately 400 parsecs (1,300 ly) away. It varies regularly in brightness between extremes of magnitude 4.4 and 6.9 roughly every 7 months. When it is near its maximum brightness, it is faintly visible to the naked eye of an observer with good observing conditions.