Astronomy:HD 34968

From HandWiki
Short description: Binary star system in the constellation Lepus
HD 34968
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lepus
Right ascension  05h 20m 26.91498s[1]
Declination −21° 14′ 23.1367″[1]
Apparent magnitude (V) 4.69 (4.73 + 8.45)[2]
Characteristics
Spectral type A0 V[3]
B−V color index −0.048±0.003[4]
Astrometry
Radial velocity (Rv)30.9±0.5[5] km/s
Proper motion (μ) RA: +17.149[1] mas/yr
Dec.: −9.382[1] mas/yr
Parallax (π)8.7188 ± 0.1661[1] mas
Distance374 ± 7 ly
(115 ± 2 pc)
Absolute magnitude (MV)−0.82[4]
Details
HD 34968 A
Mass3.34±0.06[6] M
Radius2.0[7] R
Luminosity245+38
−33
[6] L
Temperature10,046+70
−69
[6] K
Rotational velocity (v sin i)84[6] km/s
Other designations
BD−21° 1135, HD 34968, HIP 24927, HR 1762, SAO 170327, WDS J05204-2114A[8]
Database references
SIMBADdata

HD 34968 is a binary star[2] system in the southern constellation Lepus. The combined apparent visual magnitude of 4.69[2] is bright enough to be visible to the naked eye. The distance to HD 34968 can be estimated from its annual parallax shift of 8.7 mas, yielding a range of 374 light years. It is moving further away from the Earth with a heliocentric radial velocity of 31 km/s,[5] having come within 118.6 ly some 3,686,000 years ago.[4]

The primary member, component A, is a magnitude 4.73 star. Houk and Smith-Moore (1978) gave this object a stellar classification of A0 V,[3] indicating it is an ordinary A-type main-sequence star. Gray and Garrison (1987) classified it as B9.5 III and noted that the spectrum is slightly variable.[9] It is 99.2%±2.6% of the way through its main sequence lifetime,[6] with 3.34[6] times the mass of the Sun and 2.0[7] times the Sun's radius. The star is spinning with a projected rotational velocity of 84 km/s.[6] It is radiating 245[6] times the Sun's luminosity from its photosphere at an effective temperature of 10,046 [6]

The fainter secondary, component B, is a magnitude 8.45[2] star at an angular separation of 4.1 along a position angle of 279°, as of 2008.[10]

References

  1. 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G. 
  2. 2.0 2.1 2.2 2.3 Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  3. 3.0 3.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1988mcts.book.....H. 
  4. 4.0 4.1 4.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  5. 5.0 5.1 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode2012A&A...537A.120Z. 
  7. 7.0 7.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics 367 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  8. "HD 34968". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+34968. 
  9. Gray, R. O.; Garrison, R. F. (December 1987), "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation", Astrophysical Journal Supplement 65: 581, doi:10.1086/191237, Bibcode1987ApJS...65..581G. 
  10. Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode2001AJ....122.3466M