Nu Leporis

Nu Leporis, Latinized from ν Leporis, is a probable astrometric binary[11] star system in the constellation Lepus. It is visible to the naked eye as a faint star with an apparent visual magnitude of 5.29.[2] Based upon an annual parallax shift of 7.70 mas as seen from the Earth,[1] it is 420 light years from the Sun.

Nu Leporis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lepus
Right ascension  05h 19m 59.02275s[1]
Declination −12° 18′ 56.1139″[1]
Apparent magnitude (V) 5.29[2]
Characteristics
Spectral type B7/8 V[3] or B7 IVnn[4]
U−B color index −0.41[2]
B−V color index −0.12[2]
Astrometry
Radial velocity (Rv)+16.0±7.4[5] km/s
Proper motion (μ) RA: −13.32[1] mas/yr
Dec.: +7.18[1] mas/yr
Parallax (π)9.78 ± 0.37[1] mas
Distance330 ± 10 ly
(102 ± 4 pc)
Absolute magnitude (MV)+0.25[6]
Details
Mass3.28±0.05[7] M☉
Radius3.0[8] R☉
Luminosity138[7] L☉
Temperature12,417[7] K
Rotational velocity (v sin i)285[9] km/s
Other designations
ν Lep, 7 Lep, BD−12° 1132, FK5 2380, GC 6538, HD 34863, HIP 24873, HR 1757, SAO 150345[10]
Database references
SIMBADdata

The visible component is a B-type star with an estimated 3.3[7] times the mass of the Sun. Lesh (1968) gave a stellar classification of B7 IVnn,[4] which would indicate this is a somewhat evolved subgiant star. The 'nn' notation indicates especially "nebulous" absorption lines caused by rapid rotation. Houk and Smith-Moore (1978) listed it as B7/8 V,[3] suggesting this is instead a B-type main sequence star that has not yet consumed all the hydrogen at its core.

Nu Leporis is spinning rapidly with a projected rotational velocity of 285 km/s.[9] The star has a radius about three[8] times that of the Sun and is radiating 138 times the Sun's luminosity from its photosphere at an effective temperature of 12,417 K.[7]

References
  1. 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. Crawford, D. L.; et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal, 76: 1058, Bibcode:1971AJ.....76.1058C, doi:10.1086/111220.
  3. 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, Bibcode:1988mcts.book.....H.
  4. Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi:10.1086/190179.
  5. 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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  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.
  7. Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.
  8. Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367 (2): 521, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  9. Abt, Helmut A.; et al. (2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573: 359, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
  10. "nu. Lep". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-18.
  11. 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.
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