HR 3220

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HR 3220
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Carina
Right ascension  08h 09m 00.67584s[1]
Declination −61° 18′ 08.7391″[1]
Apparent magnitude (V) 4.75[2]
Spectral type F6 V Fe-0.8 CH-0.4[3]
U−B color index −0.05[2]
B−V color index +0.44[2]
Radial velocity (Rv)+23.7[4] km/s
Proper motion (μ) RA: −150.05[1] mas/yr
Dec.: −296.87[1] mas/yr
Parallax (π)50.05 ± 2.65[1] mas
Distance65 ± 3 ly
(20 ± 1 pc)
Absolute magnitude (MV)+3.19[5]
Mass1.35[6] M
Surface gravity (log g)4.12[6] cgs
Temperature6,365[6] K
Metallicity [Fe/H]−0.27[6] dex
Rotational velocity (v sin i)8.8[5] km/s
Age10[6] Gyr
Other designations
B Carinae, CP−60°1074, FK5 2636, Gl 297.1, HD 68456 HIP 39903, HR 3220, SAO 250131
Database references

HR 3220 (B Car) is a single-lined spectroscopic binary in the constellation Carina, approximately 65 light years from Earth. The primary is a F-type main sequence star with an apparent magnitude of +4.75. The secondary is most likely a helium white dwarf with 0.47 times the mass of the Sun. Mass transfer from the white dwarf progenitor has given the primary the spectral signature of a blue straggler that appears much younger than its actual age of about 10 billion years.[6]


  1. ^ a b c d e van Leeuwen, F. (November 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. ^ a b c Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637.
  4. ^ Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics, 418: 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959.
  5. ^ a b Ammler-von Eiff, M.; Reiners, A. (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: 31, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, A116.
  6. ^ a b c d e f Fuhrmann, K.; et al. (September 2011), "Discovery of the nearby F6V star HR 3220 as a field blue straggler", Monthly Notices of the Royal Astronomical Society, 416 (1): 391–392, Bibcode:2011MNRAS.416..391F, doi:10.1111/j.1365-2966.2011.19042.x