Theta2 Orionis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| A | |
| Right ascension | 05h 35m 22.90124s |
| Declination | −05° 24′ 57.8326″ |
| Apparent magnitude (V) | 5.02 |
| B | |
| Right ascension | 05h 35m 26.40075s |
| Declination | −05° 25′ 00.7938″ |
| Apparent magnitude (V) | 6.380 |
| C | |
| Right ascension | 05h 35m 31.43111s |
| Declination | −05° 25′ 16.3717″ |
| Apparent magnitude (V) | 8.18 |
| Characteristics | |
| Spectral type | O9.5IVp + B0.7V + B5V |
| Astrometry | |
| A | |
| Radial velocity (Rv) | 35.6 km/s |
| Proper motion (μ) | RA: +2.630 mas/yr Dec.: +2.394 mas/yr |
| Parallax (π) | 2.9728±0.2136 mas |
| Distance | 1,100 ± 80 ly (340 ± 20 pc) |
| Absolute magnitude (MV) | −4.3 |
| B | |
| Proper motion (μ) | RA: +1.161 mas/yr Dec.: +0.162 mas/yr |
| Parallax (π) | 2.3870±0.0499 mas |
| Distance | 1,370 ± 30 ly (419 ± 9 pc) |
| Absolute magnitude (MV) | −2.60 |
| C | |
| Proper motion (μ) | RA: +2.510 mas/yr Dec.: +3.731 mas/yr |
| Parallax (π) | 2.4513±0.0380 mas |
| Distance | 1,330 ± 20 ly (408 ± 6 pc) |
| Absolute magnitude (MV) | −0.6 |
| Details | |
| A | |
| Mass | 39 M☉ |
| Luminosity | 107,000 L☉ |
| Temperature | 34,900 K |
| Rotational velocity (v sin i) | 133 km/s |
| B | |
| Mass | 14.8 M☉ |
| Radius | 4.3 R☉ |
| Luminosity | 12,300 L☉ |
| Surface gravity (log g) | 4.30 cgs |
| Temperature | 29,300 K |
| Rotational velocity (v sin i) | 33 km/s |
| Age | <2 Myr |
| C | |
| Mass | 4.86 M☉ |
| Luminosity | 616 L☉ |
| Temperature | 13,800 K |
| Rotational velocity (v sin i) | 78 km/s |
| Age | <1 Myr |
| Other designations | |
| θ2 Ori, STF 4016, WDS J05354-0525, ADS 4188 | |
| θ2 Ori A: 43 Ori, HR 1897, BD−05°1319, HD 37041, SAO 132321, HIP 26235, CCDM 05353-0524E | |
| θ2 Ori B: BD−05°1320, HD 37042, SAO 132322, CCDM 05353-0524F | |
| θ2 Ori C: V361 Ori, BD−05°1326, HD 37062, SAO 132329, S 490A, CCDM 05353-0524G | |
| Database references | |
| SIMBAD | data |
| data2 | |
| data3 | |
Theta2 Orionis (θ2 Ori) is a multiple star system in the constellation Orion. It is a few arc minutes from its more famous neighbour the Trapezium Cluster, also known as θ1 Orionis.