42 Orionis is a class B1V[3] (blue main-sequence) star in the constellation Orion. Its apparent magnitude is 4.59[2] and it is approximately 900 light years away based on parallax.[1]

42 Orionis
Location of 42 Orionis (marked red)
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
Right ascension 05h 35m 23.16427s[1]
Declination −4° 50′ 18.0881″[1]
Apparent magnitude (V) 4.59[2]
Characteristics
Spectral type B1V[3]
U−B color index -0.94[2]
B−V color index -0.19[2]
Astrometry
Radial velocity (Rv)+28.40[4] km/s
Proper motion (μ) RA: +4.52[1] mas/yr
Dec.: -7.11[1] mas/yr
Parallax (π)3.69 ± 1.20 mas[1]
Distanceapprox. 900 ly
(approx. 270 pc)
Details
Mass12.0[5] M
Radius15.6 R
Luminosity10737 L
Temperature25,400[6] K
Rotational velocity (v sin i)20[7] km/s
Other designations
c Orionis, BD-04°1185, CCDM J05354-0450AB, GC 6934, HIP 26237, HR 1892, HD 37018, NSV 2318, SAO 132320, WDS J05354-0450AB
Database references
SIMBADdata
42 Ori is the bright star at the centre of NGC 1977.

The primary star, Aa, has one spectroscopic companion Ab of magnitude 6.3 and separation 0.16", and a more distant companion B of 7.5 magnitude at 1.6" separation.[8][9]

c Orionis is surrounded by NGC 1977 one of a smaller fainter group of named nebulae just north of the Orion Nebula. c Ori is the star which excites and illuminates NGC 1977.

References

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  1. ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog entry
  2. ^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ a b Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
  4. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  5. ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873. Vizier catalog entry
  6. ^ Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349. arXiv:1003.2335. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. S2CID 111387483. Vizier catalog entry
  7. ^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573 (1): 359–365. Bibcode:2002ApJ...573..359A. doi:10.1086/340590.
  8. ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
  9. ^ Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Mendez, Rene A.; Horch, Elliott P. (2015). "Speckle Interferometry at Soar in 2014". The Astronomical Journal. 150 (2): 50. arXiv:1506.05718. Bibcode:2015AJ....150...50T. doi:10.1088/0004-6256/150/2/50. S2CID 30737411.