Theta1 Orionis A
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 35m 15.84743s |
| Declination | −05° 23′ 14.3441″ |
| Apparent magnitude (V) | 6.72 - 7.65 |
| Characteristics | |
| Spectral type | B0.5V |
| Variable type | Algol |
| Astrometry | |
| Proper motion (μ) | RA: 4.81±0.10 mas/yr Dec.: −2.53±0.12 mas/yr |
| Parallax (π) | 2.626±0.100 mas |
| Distance | 1,240 ± 50 ly (380 ± 10 pc) |
| Absolute magnitude (MV) | −2.80 |
| Details | |
| A1 | |
| Mass | 15.3 M☉ |
| Radius | 4.5 R☉ |
| Luminosity | 16,200 L☉ |
| Surface gravity (log g) | 4.30 cgs |
| Temperature | 30,700 K |
| Age | <2.5 Myr |
| A3 | |
| Mass | 2.5 - 2.7 M☉ |
| Radius | 6.4 R☉ |
| Details | |
| A2 | |
| Mass | 4 M☉ |
| Other designations | |
| 41 Ori A, V1016 Ori, BD−05 1315A, HD 37020, HIP 26220, HR 1893 | |
| Database references | |
| SIMBAD | data |
Theta1 Orionis A (θ1 Ori A) is a variable trinary star in the constellation Orion. Its apparent magnitude range is 6.72 to 7.65 with a period of 65.432 days. It is one of the main stars in The Trapezium in Orion, along with B, C, and D, as well as the fainter E.