HD 49976

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HD 49976
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Monoceros
Right ascension  06h 50m 42.30364s[1]
Declination –08° 02′ 27.5937″[1]
Apparent magnitude (V) 6.306
Spectral type A2p Sr Cr Eu[2]
U−B color index +0.02[3]
B−V color index +0.00[3]
Variable type α2 CVn
Radial velocity (Rv)22.4[4] km/s
Proper motion (μ) RA: –8.68[1] mas/yr
Dec.: +2.07[1] mas/yr
Parallax (π)10.01 ± 0.40[1] mas
Distance330 ± 10 ly
(100 ± 4 pc)
Absolute magnitude (MV)+1.13[5]
Mass2.21±0.11[5] M
Radius2.3±0.3[5] R
Luminosity32[5] L
Surface gravity (log g)4.04±0.13[5] cgs
Temperature9,016[5] K
Rotation2.976 days[5]
Rotational velocity (v sin i)31[6] km/s
Other designations
V592 Monocerotis, BD−07° 1592, HD 49976, HIP 32838, HR 2534, SAO 133761.
Database references

HD 49976, also known as V592 Monocerotis, is a variable star in the constellation of Monoceros (the Unicorn). It is a chemically peculiar star showing excesses in strontium and the rare earth elements in the photosphere, among others. The magnetic field is complex; not corresponding to a simple dipole.[7]


  1. ^ a b c d e 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. ^ Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819
  3. ^ a b Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J
  4. ^ Babcock, Horace W. (January 1958), "A Catalog of Magnetic Stars.", Astrophysical Journal Supplement, 3: 141, Bibcode:1958ApJS....3..141B, doi:10.1086/190035
  5. ^ a b c d e f g North, P. (June 1998), "Do SI stars undergo any rotational braking?", Astronomy and Astrophysics, 334: 181–187, arXiv:astro-ph/9802286, Bibcode:1998A&A...334..181N
  6. ^ Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393: 897–911, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943
  7. ^ Glagolevskij, Yu. V.; et al. (October 2013), "Features of calcium and strontium distribution on the surface of CP star HD49976", Astrophysical Bulletin, 68 (4): 454–460, Bibcode:2013AstBu..68..454G, doi:10.1134/S1990341313040068