HR 3220
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina |
| Right ascension | 08h 09m 00.56958s |
| Declination | −61° 18′ 08.5836″ |
| Apparent magnitude (V) | 4.75 |
| Characteristics | |
| Evolutionary stage | Blue straggler |
| Spectral type | F6 V Fe-0.8 CH-0.4 |
| U−B color index | −0.05 |
| B−V color index | +0.44 |
| Astrometry | |
| Radial velocity (Rv) | +23.7 km/s |
| Proper motion (μ) | RA: −113.750 mas/yr Dec.: −297.923 mas/yr |
| Parallax (π) | 55.3398±0.5399 mas |
| Distance | 58.9 ± 0.6 ly (18.1 ± 0.2 pc) |
| Absolute magnitude (MV) | +3.19 |
| Orbit | |
| 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 M☉ |
| Radius | 1.50+0.13 −0.06 R☉ |
| Luminosity | 3.6±0.4 L☉ |
| Surface gravity (log g) | 4.12 cgs |
| Temperature | 6491+127 −259 K |
| Metallicity [Fe/H] | −0.27 dex |
| Rotational velocity (v sin i) | 8.8 km/s |
| Age | 10 Gyr |
| B | |
| Mass | 0.42+0.09 −0.05 M☉ |
| Other designations | |
| B Car, CPD−60°1074, FK5 2636, GJ 297.1, HD 68456, HIP 39903, HR 3220, SAO 250131 | |
| Database references | |
| SIMBAD | data |
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. 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.
This is a single-lined spectroscopic binary system with an orbital period of 2.46 years and an eccentricity of 0.12. The visible component is an F-type main sequence star with a stellar classification of F6 V Fe-0.8 CH-0.4, 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.