n Centauri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Centaurus
Right ascension 12h 53m 26.20s[1]
Declination −40° 10′ 43.9″[1]
Apparent magnitude (V) +4.25[2]
Characteristics
Spectral type A7IV[3] or A7V[4]
B−V color index +0.224±0.014[2]
Astrometry
Proper motion (μ) RA: +70.84±0.14[1] mas/yr
Dec.: −22.54±0.10[1] mas/yr
Parallax (π)21.95 ± 0.19 mas[1]
Distance149 ± 1 ly
(45.6 ± 0.4 pc)
Absolute magnitude (MV)+0.86[5]
Details
Mass1.62[6] M☉
Luminosity34.34[2] L☉
Surface gravity (log g)3.87±0.14[6] cgs
Temperature7,835±266[6] K
Rotational velocity (v sin i)92.4±4.6[5] km/s
Age401[6] Myr
Other designations
n Cen, CD−39° 7893, FK5 482, GC 17489, GJ 488.1, HD 111968, HIP 62896, HR 4889, SAO 203907[7]
Database references
SIMBADdata

HD 111968, also known by the Bayer designation n Centauri, is a single[8] star in the southern constellation of Centaurus. It is a white-hued star that is faintly visible to the naked eye with an apparent visual magnitude of +4.25.[2] The star is located at a distance of approximately 149 light years from the Sun based on parallax.[1] The radial velocity of the star is poorly constrained, with an estimated value of 2.5 km/s.[2]

This is classified as an A-type star but there has been disagreement about the luminosity class. A. de Vaucouleurs in 1957 found a class of III, suggesting this is an evolved giant star.[9] O. J. Eggen gave a class of V in 1962,[10] as did R. O. Gray and R. F. Garrison in 1989,[4] indicating this is a main sequence star. In 1979, N. Houk found a class of IV,[3] meaning this is a subgiant star.

HD 111968 is a young star, some 400 million years old, with 1.6 times the mass of the Sun.[6] It is spinning with a projected rotational velocity of 92 km/s.[5] The star is radiating 34[2] times the luminosity of the Sun from its photosphere at an effective temperature of 7,835 K.[6]

References

  1. 1 2 3 4 5 6 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. 1 2 3 4 5 6 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: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
  4. 1 2 Gray, R. O.; Garrison, R. F. (1989), "The Late A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation", The Astrophysical Journal Supplement Series, 70: 623, Bibcode:1989ApJS...70..623G, doi:10.1086/191349.
  5. 1 2 3 Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
  6. 1 2 3 4 5 6 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. ↑ "n Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-01.
  8. ↑ 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.
  9. ↑ 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.
  10. ↑ Eggen, O. J. (1962), "Space-velocity vectors for 3483 stars with proper motion and radial velocity", Royal Observatory Bulletin, 51, Bibcode:1962RGOB...51...79E.
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