Astronomy:HR 3220

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Short description: Binary star system in the constellation Carina
HR 3220
Location of HR 3220 (circled in red)
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
Evolutionary stage Blue straggler[3]
Spectral type F6 V Fe-0.8 CH-0.4[4]
U−B color index −0.05[2]
B−V color index +0.44[2]
Astrometry
Radial velocity (Rv)+23.7[5] 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[6]
Orbit[7]
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[3] M☉
Radius1.50+0.13
−0.06
[1] R☉
Luminosity3.6±0.4[1] L☉
Surface gravity (log g)4.12[3] cgs
Temperature6491+127
−259
[1] K
Metallicity [Fe/H]−0.27[3] dex
Rotational velocity (v sin i)8.8[6] km/s
Age10[3] Gyr
B
Mass0.42+0.09
−0.05
[3] 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.[5]

This is a single-lined spectroscopic binary system with an orbital period of 2.46 years and an eccentricity of 0.12.[7] The visible component is an F-type main sequence star with a stellar classification of F6 V Fe-0.8 CH-0.4,[4] 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.[3]

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. Bibcode: 2018A&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), Bibcode: 1986EgUBV........0M. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 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, Bibcode: 2011MNRAS.416..391F 
  4. ↑ 4.0 4.1 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, Bibcode: 2006AJ....132..161G. 
  5. ↑ 5.0 5.1 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, Bibcode: 2004A&A...418..989N. 
  6. ↑ 6.0 6.1 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, Bibcode: 2012A&A...542A.116A. 
  7. ↑ 7.0 7.1 Murdoch, K.; Hearnshaw, J. B. (June 1993), "The orbit of the spectroscopic binary HR 3220", The Observatory 113: 126–127, Bibcode: 1993Obs...113..126M. 
  8. ↑ "HD 68456". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+68456.