Pi Virginis
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[1] mas |
Distance | 380 ± 20 ly (118 ± 5 pc) |
Orbit[5] | |
Period (P) | 282.69 d |
Eccentricity (e) | 0.27 |
Semi-amplitude (K1) (primary) | 26.20 km/s |
Details | |
π Vir A | |
Mass | 2.2[5] M☉ |
Radius | 1.5[6] R☉ |
Surface gravity (log g) | 3.51[7] cgs |
Temperature | 8,000[7] K |
Rotational velocity (v sin i) | 71[3] km/s |
Other designations | |
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.
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.[5] 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.[7]
References
- 1 2 3 4 5 6 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- 1 2 3 4 Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M.
- 1 2 Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
- ↑ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, eds., "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E.
- 1 2 3 Ducati, J. R.; et al. (January 2011), "The mass ratio and initial mass functions in spectroscopic binaries", Astronomy and Astrophysics, 525: 9, Bibcode:2011A&A...525A..26D, doi:10.1051/0004-6361/200913895, A26.
- ↑ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
- 1 2 3 Paunzen, E.; et al. (February 2013), "A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society, 429 (1): 119−125, arXiv:1211.1535, Bibcode:2013MNRAS.429..119P, doi:10.1093/mnras/sts318.
- ↑ "pi. Vir -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-16.
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