Theta2 Orionis

For other stars with this Bayer designation, see θ Orionis.
θ2 Orionis

The three components of θ2 Orionis, plus nearby stars
Credit: Ian Nartowicz (derived from ESA/Hubble image)
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
A
Right ascension 05h 35m 22.90124s[1]
Declination −05° 24′ 57.8326″[1]
Apparent magnitude (V) 5.02[2]
B
Right ascension 05h 35m 26.40075s[3]
Declination −05° 25′ 00.7938″[3]
Apparent magnitude (V) 6.380[4]
C
Right ascension 05h 35m 31.43111s[5]
Declination −05° 25′ 16.3717″[5]
Apparent magnitude (V) 8.18[6]
Characteristics
Spectral type O9.5IVp[7] + B0.7V[8] + B5V[9]
Astrometry
A
Radial velocity (Rv)35.6[10] km/s
Proper motion (μ) RA: +2.630[1] mas/yr
Dec.: +2.394[1] mas/yr
Parallax (π)2.9728 ± 0.2136 mas[1]
Distance1,100 ± 80 ly
(340 ± 20 pc)
Absolute magnitude (MV)−4.3[11]
B
Proper motion (μ) RA: +1.161[3] mas/yr
Dec.: +0.162[3] mas/yr
Parallax (π)2.3870 ± 0.0499 mas[3]
Distance1,370 ± 30 ly
(419 ± 9 pc)
Absolute magnitude (MV)−2.60[4]
C
Proper motion (μ) RA: +2.510[5] mas/yr
Dec.: +3.731[5] mas/yr
Parallax (π)2.4513 ± 0.0380 mas[5]
Distance1,330 ± 20 ly
(408 ± 6 pc)
Absolute magnitude (MV)−0.6[12]
Details
A
Mass39[13] M☉
Luminosity107,000[14] L☉
Temperature34,900[14] K
Rotational velocity (v sin i)133[8] km/s
B
Mass14.8[4] M☉
Radius4.3[4] R☉
Luminosity12,300[4] L☉
Surface gravity (log g)4.30[4] cgs
Temperature29,300[4] K
Rotational velocity (v sin i)33[8] km/s
Age<2[4] Myr
C
Mass4.86[14] M☉
Luminosity616[14] L☉
Temperature13,800[14] K
Rotational velocity (v sin i)78[15] km/s
Age<1[15] 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
SIMBADdata
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.

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