HD 91942

This article is about r Carinae. For the variable star, see R Carinae.
HD 91942
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Carina
Right ascension 10h 35m 35.29721s[1]
Declination −57° 33′ 27.4835″[1]
Apparent magnitude (V) 4.45[2]
Characteristics
Evolutionary stage Bright giant[3]
Spectral type K3II-IIb[4]
B−V color index 1.604±0.004[2]
Variable type Suspected[5]
Astrometry
Radial velocity (Rv)+9.9±0.7[2] km/s
Proper motion (μ) RA: −15.93[1] mas/yr
Dec.: +0.49[1] mas/yr
Parallax (π)2.77 ± 0.17 mas[1]
Distance1,180 ± 70 ly
(360 ± 20 pc)
Absolute magnitude (MV)−3.77[2]
Details
Mass8.1±0.7[6] M☉
Radius155.5+5.6
−11.3[7] R☉
Luminosity5,485±693[7] L☉
Surface gravity (log g)2.0[3] cgs
Temperature3,983+152
−69[7] K
Metallicity [Fe/H]0.0[3] dex
Rotational velocity (v sin i)5.8[3] km/s
Age35.7±8.3[6] Myr
Other designations
r Car, NSV 4904, CPD−56°3544, FK5 393, GC 14570, HD 91942, HIP 51849, HR 4159, SAO 238222[8]
Database references
SIMBADdata

HD 91942 is a single[9] variable star in the constellation Carina. It has the Bayer designation r Carinae, while HD 91942 is the identifier from the Henry Draper catalogue. This orange-hued object is visible to the naked eye with an apparent visual magnitude of 4.45.[2] Based on parallax measurements, it is located at a distance of approximately 1,180 light years from the Sun.[1] The star has an absolute magnitude of −3.77,[2] and is drifting further away with a radial velocity of +9.9 km/s.[2]

This object is a massive, aging bright giant with a stellar classification of K3II-IIb.[4] It is a suspected variable star that fluctuates in magnitude by an amplitude of 0.05 in the B-band of the UBV photometric system.[5] With the supply of hydrogen exhausted at its core, it has evolved of the main sequence and cooled and expanded to 156[7] times the Sun's radius. It is an estimated 36[6] million years old with eight[6] times the mass of the Sun. It is radiating around 5,500[7] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,983 K.[7]

References

  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.
  2. ^ a b c d e f g Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. ^ a b c d Lèbre, A.; de Laverny, P.; Do Nascimento, J. D. Jr.; de Medeiros, J. R. (May 2006), "Lithium abundances and rotational behavior for bright giant stars", Astronomy and Astrophysics, 450 (3): 1173–1179, Bibcode:2006A&A...450.1173L, doi:10.1051/0004-6361:20053485.
  4. ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
  5. ^ a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  6. ^ a b c d Tetzlaff, N.; et al. (January 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.
  7. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  8. ^ "HD 91942". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-30.
  9. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.