HD 79940

Last updated
HD 79940
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Vela
Right ascension 09h 15m 45.07943s [1]
Declination −37° 24 47.3124 [1]
Apparent magnitude  (V)4.63 [2]
Characteristics
Spectral type F3/5V [3] or F5III [4] [5]
B−V color index 0.473±0.002 [2]
Astrometry
Radial velocity (Rv)+5.8±2.8 [2] km/s
Proper motion (μ)RA: +14.128 [1] mas/yr
Dec.: −8.111 [1] mas/yr
Parallax (π)20.5985±0.1895  mas [1]
Distance 158 ± 1  ly
(48.5 ± 0.4  pc)
Absolute magnitude  (MV)1.12 [2]
Details [6]
Mass 1.36 [6]   M
Radius 4.35+0.11
−0.19
[1]   R
Luminosity 28.427±0.305 [1]   L
Surface gravity (log g)3.26±0.14 [6]   cgs
Temperature 6,388+143
−76
[1]   K
Metallicity [Fe/H]0.20±0.15 [2]   dex
Rotational velocity (v sin i)117.2±5.9 [7]  km/s
Age 2.76 [6]   Gyr
Other designations
k1 Vel, CD−36 5505, GJ 339.3, GJ 9293, HD 79940, HIP 45448, HR 3684, SAO 200163, WDS J09158-3725A [8]
Database references
SIMBAD data

HD 79940 is a single [9] star in the southern constellation of Vela. It has the Bayer designation of k1 Velorum; HD 79940 is the identifier from the Henry Draper Catalogue . This star has a yellow-white hue and is faintly visible to the naked eye as a point light source with an apparent visual magnitude of 4.63. [2] It is located at a distance of approximately 158  light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +6 km/s. [2]

There has been some disagreement over the stellar classification of this star. In 1975, S. Maladora found a class of F5III, suggesting an evolved F-type star, [4] matching an earlier (1957) classification by A. de Vaucouleurs. [5] N. Houk assigned it a class of F3/5V in 1979, matching an F-type main-sequence star. [3] It has a high rate of spin with a projected rotational velocity of 117.2±5.9 km/s. [7] This may explain why it was incorrectly classified as a spectroscopic binary in 1972. [9]

There is a faint magnitude 14.50 companion at an angular separation of 11.3 along a position angle of 126° from the brighter star. This was discovered by T. J. J. See in 1897. [10]

References

  1. 1 2 3 4 5 6 7 8 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.
  2. 1 2 3 4 5 6 7 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. 1 2 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
  4. 1 2 Malaroda, S. (August 1975), "Study of the F-type stars. I. MK spectral types.", Astronomical Journal, 80: 637–641, Bibcode:1975AJ.....80..637M, doi: 10.1086/111786 .
  5. 1 2 de Vaucouleurs, A. (1957). "Spectral types and luminosities of B, A and F southern stars". Monthly Notices of the Royal Astronomical Society. 117 (4): 449. Bibcode:1957MNRAS.117..449D. doi: 10.1093/mnras/117.4.449 .
  6. 1 2 3 4 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv: 1501.03154 , Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID   33401607.
  7. 1 2 Reiners, Ansgar (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, arXiv: astro-ph/0509399 , Bibcode:2006A&A...446..267R, doi:10.1051/0004-6361:20053911, S2CID   8642707
  8. "HD 79940". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-09-28.
  9. 1 2 Kunzli, M.; North, P. (January 1998), "Are metallic A-F giants evolved AM stars? Rotation and rate of binaries among giant F stars", Astronomy and Astrophysics Supplement, 127 (2): 277–294, arXiv: astro-ph/9710226 , Bibcode:1998A&AS..127..277K, doi:10.1051/aas:1998350, S2CID   7535170.
  10. Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi: 10.1086/323920 .