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]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| 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 mas[1] |
| Distance | 58.9 ± 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 | |
| Mass | 1.35[7] M☉ |
| Radius | 1.50+0.13 −0.06[1] R☉ |
| Luminosity | 3.6±0.4[1] L☉ |
| Surface gravity (log g) | 4.12[7] cgs |
| Temperature | 6491+127 −259[1] K |
| Metallicity [Fe/H] | −0.27[7] dex |
| Rotational velocity (v sin i) | 8.8[5] km/s |
| Age | 10[7] Gyr |
| B | |
| Mass | 0.42+0.09 −0.05[7] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
edit- ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b 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, S2CID 119476992.
- ^ a b 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, S2CID 11027621.
- ^ a b 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, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
- ^ a b Murdoch, K.; Hearnshaw, J. B. (June 1993), "The orbit of the spectroscopic binary HR 3220", The Observatory, 113: 126–127, Bibcode:1993Obs...113..126M.
- ^ 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
- ^ "HD 68456". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-12-04.