Pi Virginis
Binary star in the constellation Virgo From Wikipedia, the free encyclopedia
Pi Virginis (π Vir, π Virginis) is a binary star in the zodiac constellation of Virgo. It is visible to the naked eye with an apparent visual magnitude of 4.64.[2] The distance to this star, based upon parallax measurements,[1] is roughly 380 light years.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 00m 52.39042s[1] |
| Declination | +06° 36′ 51.5571″[1] |
| Apparent magnitude (V) | 4.64[2] |
| Characteristics | |
| Spectral type | A5 V[3] |
| U−B color index | +0.12[2] |
| B−V color index | +0.12[2] |
| Astrometry | |
| Radial velocity (Rv) | −10.4[4] km/s |
| Proper motion (μ) | RA: +0.26[1] mas/yr Dec.: −30.10[1] mas/yr |
| Parallax (π) | 8.49±0.39 mas[1] |
| Distance | 380 ± 20 ly (118 ± 5 pc) |
| Absolute magnitude (MV) | −0.70[5] |
| Orbit[6] | |
| Primary | π Virginis A |
| Companion | π Virginis B |
| Period (P) | 282.69 days |
| Semi-major axis (a) | 3.55 mas |
| Eccentricity (e) | 0.265 |
| Inclination (i) | 62.71° |
| Longitude of the node (Ω) | 149.34° |
| Periastron epoch (T) | 2448281.3906 |
| Argument of periastron (ω) (secondary) | 312° |
| Semi-amplitude (K1) (primary) | 26.20[7] km/s |
| Details | |
| π Vir A | |
| Mass | 2.2[7] M☉ |
| Radius | 1.5[8] R☉ |
| Surface gravity (log g) | 3.51[9] cgs |
| Temperature | 8,000[9] K |
| Rotational velocity (v sin i) | 71[3] km/s |
| Other designations | |
| BD+07°2502, FK5 1311, HD 104321, HIP 58590, HR 4589, SAO 119164[10] | |
| Database references | |
| SIMBAD | data |
This is a spectroscopic binary system with a stellar classification of A5V. They have an orbital period of 283 days with an eccentricity of 0.27.[7] The mass ratio of the two stars is about 0.47, with the primary having an estimated mass of around 2.2 times that of the Sun. The primary is a cool metallic-lined Am star.[9]
References
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