GW Orionis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 29m 08.3929s |
| Declination | +11° 52′ 12.666″ |
| Apparent magnitude (V) | 9.7–10.4 |
| Characteristics | |
| Spectral type | G8V or G3V/K0V |
| Variable type | T Tau |
| Astrometry | |
| Radial velocity (Rv) | 28.33±0.18 km/s |
| Proper motion (μ) | RA: −2.351±0.061 mas/yr Dec.: −0.396±0.043 mas/yr |
| Parallax (π) | 2.4510±0.0623 mas |
| Distance | 1,330 ± 30 ly (410 ± 10 pc) |
| Orbit | |
| Primary | GW Orionis A |
| Companion | GW Orionis B |
| Period (P) | 241.50±0.05 d |
| Semi-major axis (a) | 1.25±0.05 AU |
| Eccentricity (e) | 0.13±0.01 |
| Inclination (i) | 151+1 −2° |
| Longitude of the node (Ω) | 263±13° |
| Periastron epoch (T) | 2456681±4 HJD |
| Argument of periastron (ω) (secondary) | 197±7° |
| Semi-amplitude (K1) (primary) | 8.34±0.15 km/s |
| Orbit | |
| Primary | GW Orionis AB |
| Companion | GW Orionis C |
| Period (P) | 4246±66 d |
| Semi-major axis (a) | 9.19±0.32 AU |
| Eccentricity (e) | 0.13±0.07 |
| Inclination (i) | 130+28 −27° |
| Longitude of the node (Ω) | 282±9° |
| Periastron epoch (T) | 2453911±260 HJD |
| Argument of periastron (ω) (secondary) | 310±21° |
| Semi-amplitude (K1) (primary) | 2.38±0.23 km/s |
| Details | |
| GW Orionis A | |
| Mass | 2.74+0.15 −0.52 M☉ |
| Temperature | 5780±100 K |
| Rotational velocity (v sin i) | 43 km/s |
| Age | 0.3–1.3 Myr |
| GW Orionis B | |
| Mass | 1.65+0.10 −0.31 M☉ |
| Temperature | 5250±100 K |
| Rotational velocity (v sin i) | 50 km/s |
| Age | 0.3–1.3 Myr |
| GW Orionis C | |
| Mass | 0.88+0.85 −0.19 M☉ |
| Age | 0.3–1.3 Myr |
| Other designations | |
| MHA 265-2, HD 244138, HIP 25689, TYC 708-1901-1, 2MASS J05290838+1152126 | |
| Database references | |
| SIMBAD | data |
GW Orionis is a T Tauri type pre-main sequence hierarchical triple star system. It is associated with the Lambda Orionis star-forming region and has an extended circumtrinary protoplanetary disk.