Pi Virginis

π 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
Distance380 ± 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
Mass2.2[5] M☉
Radius1.5[6] R☉
Surface gravity (log g)3.51[7] cgs
Temperature8,000[7] 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.[8]

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. 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:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
  2. 1 2 3 4 Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M.
  3. 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/0610785Freely accessible, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
  4. ↑ 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.
  5. 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.
  6. ↑ 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/0012289Freely accessible, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  7. 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:1211.1535Freely accessible, Bibcode:2013MNRAS.429..119P, doi:10.1093/mnras/sts318.
  8. ↑ "pi. Vir -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-16.
This article is issued from Wikipedia - version of the 9/16/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.