HD 76728 is a suspected astrometric binary[7] star system in the constellation Carina. It has the Bayer designation c Carinae; HD 76728 is the identifier from the Henry Draper catalogue. The visible component has a blue-white hue and is visible to the naked eye with an apparent visual magnitude of +3.84.[2] The system is located at a distance of approximately 320 light years from the Sun based on parallax,[1] and it is drifting further away with a radial velocity of around +25 km/s.[2] It is a candidate member of the Volans-Carina Association of co-moving stars.[8]

HD 76728
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Carina
Right ascension 08h 55m 02.82822s[1]
Declination −60° 38′ 40.5998″[1]
Apparent magnitude (V) +3.84[2]
Characteristics
Evolutionary stage Bright giant
Spectral type B8/9II[3]
B−V color index −0.104±0.006[2]
Variable type Constant[4]
Astrometry
Radial velocity (Rv)+25.0±4.1[2] km/s
Proper motion (μ) RA: −28.18[1] mas/yr
Dec.: +41.48[1] mas/yr
Parallax (π)10.20 ± 0.10 mas[1]
Distance320 ± 3 ly
(98.0 ± 1.0 pc)
Absolute magnitude (MV)−1.12[2]
Details
Radius5.0[5] R
Luminosity449.05[2] L
Temperature11,880[5] K
Other designations
c Car, CD−60°1243, FK5 336, GC 12359, HD 76728, HIP 43783, HR 3571, SAO 250374, CCDM J08550-6039, WDS J08550-6039A[6]
Database references
SIMBADdata

The visible component is an aging bright giant star with a stellar classification of B8/9II.[3] The spectrum of the star displays metallic lines of magnesium.[9] The Volans-Carina Association to which it belongs has an age of 90 million years.[8] The star has five[5] times the radius of the Sun and is radiating 449[2] times the Sun's luminosity from its photosphere at an effective temperature of 11,880 K.[5]

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.
  2. ^ a b c d e f g h 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 Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H
  4. ^ Adelman, S. J.; et al. (September 2000), "On the Variability of O and B Supergiants", Information Bulletin on Variable Stars, 4946: 1, Bibcode:2000IBVS.4946....1A.
  5. ^ a b c d Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189 (3): 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601
  6. ^ "HD 76728". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-20.
  7. ^ 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
  8. ^ a b Gagné, Jonathan; et al. (October 2018), "Volans-Carina: A New 90 Myr Old Stellar Association at 85 pc", The Astrophysical Journal, 865 (2): 13, arXiv:1808.04420, Bibcode:2018ApJ...865..136G, doi:10.3847/1538-4357/aadaed, S2CID 119402144, 136.
  9. ^ Garrison, R. F.; Gray, R. O. (April 1994), "The Late B-Type Stars: Refined MK Classification, Confrontation With Stromgren Photometry, And The Effects of Rotation", Astronomical Journal, 107: 1556, Bibcode:1994AJ....107.1556G, doi:10.1086/116967.