Astronomy:HR 3220

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Short description: Binary star system in the constellation Carina
HR 3220
Observation data
Equinox J2000.0]] (ICRS)
Constellation Carina
Right ascension  08h 09m 00.56958s[1]
Declination −61° 18′ 08.5836″[1]
Apparent magnitude (V) 4.75[2]
Characteristics
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]
Astrometry
Radial velocity (Rv)+23.7[4] km/s
Proper motion (μ) RA: −113.750[1] mas/yr
Dec.: −297.923[1] mas/yr
Parallax (π)55.3398 ± 0.5399[1] mas
Distance58.9 ± 0.6 ly
(18.1 ± 0.2 pc)
Absolute magnitude (MV)+3.19[5]
Orbit[6]
Period (P)899.3±0.4 d
Semi-major axis (a)≥39.0±0.7 Gm
Eccentricity (e)0.119±0.012
Periastron epoch (T)1,845±18
Argument of periastron (ω)
(secondary)
135±5°
Semi-amplitude (K1)
(primary)
3.18±0.06 km/s
Details
A
Mass1.35[7] M
Radius1.50+0.13
−0.06
[1] R
Luminosity3.6±0.4[1] L
Surface gravity (log g)4.12[7] cgs
Temperature6491+127
−259
[1] K
Metallicity [Fe/H]−0.27[7] dex
Rotational velocity (v sin i)8.8[5] km/s
Age10[7] Gyr
B
Mass0.42+0.09
−0.05
[7] M
Other designations
B Car, CPD−60°1074, FK5 2636, GJ 297.1, HD 68456, HIP 39903, HR 3220, SAO 250131[8]
Database references
SIMBADdata

HR 3220 is a binary star system in the southern constellation of Carina. It has the Bayer designation B Carinae; HR 3220 is the designation from the Bright Star Catalogue. It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude of 4.75.[2] Based upon parallax measurements, it is located at a distance of 59 light years from the Sun. The system is drifting further away with a radial velocity of +24 km/s.[4]

This is a single-lined spectroscopic binary system with an orbital period of 2.46 years and an eccentricity of 0.12.[6] The visible component is an F-type main sequence star with a stellar classification of F6 V Fe-0.8 CH-0.4,[3] where the suffix notation indicates mild but anomalous underabundances of iron and the methylidyne radical. 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.[7]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 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.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode1986EgUBV........0M. 
  3. 3.0 3.1 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, doi:10.1086/504637, Bibcode2006AJ....132..161G. 
  4. 4.0 4.1 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, doi:10.1051/0004-6361:20035959, Bibcode2004A&A...418..989N. 
  5. 5.0 5.1 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, doi:10.1051/0004-6361/201118724, Bibcode2012A&A...542A.116A. 
  6. 6.0 6.1 Murdoch, K.; Hearnshaw, J. B. (June 1993), "The orbit of the spectroscopic binary HR 3220", The Observatory 113: 126–127, Bibcode1993Obs...113..126M. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 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, doi:10.1111/j.1365-2966.2011.19042.x, Bibcode2011MNRAS.416..391F 
  8. "HD 68456". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+68456.