23 Orionis
Double star in the constellation Orion
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23 Orionis is a double star located around 1,200 light-years (370 parsecs)[1] away from the Sun in the equatorial constellation of Orion.[12] It is visible to the naked eye as a dim, blue-white-hued point of light with a combined apparent visual magnitude of 4.99.[2] The pair are moving away from the Earth with a heliocentric radial velocity of +18 km/s,[5] and they are members of the Orion OB1 association, subgroup 1a.[13]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 22m 50.00474s[1] |
| Declination | +03° 32′ 39.9770″[1] |
| Apparent magnitude (V) | 4.99[2] (4.95 + 6.76)[3] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | B1Ⅴ[4] + B3Ⅴn[4] |
| B−V color index | −0.096±0.004[2] |
| Astrometry | |
| Absolute magnitude (MV) | −2.93[2] |
| 23 Ori A | |
| Radial velocity (Rv) | +18.0±3.7[5] km/s |
| Proper motion (μ) | RA: −2.414[1] mas/yr Dec.: +1.230[1] mas/yr |
| Parallax (π) | 2.7199±0.3155 mas[1] |
| Distance | approx. 1,200 ly (approx. 370 pc) |
| 23 Ori B | |
| Radial velocity (Rv) | 28[6] km/s |
| Proper motion (μ) | RA: +1.275[7] mas/yr Dec.: −0.552[7] mas/yr |
| Parallax (π) | 2.5579±0.0864 mas[7] |
| Distance | 1,280 ± 40 ly (390 ± 10 pc) |
| Details | |
| 23 Ori A | |
| Mass | 12.5±0.6[4] M☉ |
| Radius | 6.97[8] R☉ |
| Luminosity | 26,546[9] L☉ |
| Surface gravity (log g) | 4.078±0.045[10] cgs |
| Temperature | 25,400[9] K |
| Rotational velocity (v sin i) | 350[11] km/s |
| Age | 15.4±0.6[4] Myr |
| 23 Ori B | |
| Mass | 6.6±0.1[4] M☉ |
| Radius | 4.71[8] R☉ |
| Luminosity | 1,620[9] L☉ |
| Temperature | 18,700[9] K |
| Rotational velocity (v sin i) | 370[11] km/s |
| Age | 22.8±2.3[4] Myr |
| Other designations | |
| 23 Ori, SAO 112697, WDS J05228+0333[12] | |
| A: BD+03°871, HD 35149, HIP 25142, HR 1770, SAO 112697 | |
| B: BD+03°872, HD 35148, HIP 25145, SAO 112699 | |
| Database references | |
| SIMBAD | data |
| B | |
Howe and Clarke (2009) catalog this as a double-lined spectroscopic binary star system[14] with a wide projected separation of 9,460 AU.[8] As of 2018, they had an angular separation of 31.9″ along a position angle of 30°.[3] The brighter member, component A, is a B-type main-sequence star with a stellar classification of B1V. The secondary, component B, is of class B3V.[11] Both stars are spinning rapidly.[11]