Theta Virginis
  | |
| Observation data EpochJ2000.0EquinoxJ2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 13h09m56.99067s[1] |
| Declination | −05° 32′ 20.4185″[1] |
| Apparent magnitude(V) | 4.37[2](4.49 + 6.83 + 9.4 + 10.4)[3] |
| Characteristics | |
| Spectral type | A1Vs[4]+? + A9m +?[3] |
| U−Bcolor index | +0.00[2] |
| B−Vcolor index | −0.02[2] |
| Astrometry | |
| Radial velocity(Rv) | −2.9[5]km/s |
| Proper motion(μ) | RA:−36.28[1]mas/yr Dec.:−31.22[1]mas/yr |
| Parallax(π) | 10.33 ± 1.09mas[1] |
| Distance | approx. 320ly (approx. 100pc) |
| Absolute magnitude(MV) | −0.52[6] |
| Details | |
| θ Vir Aa | |
| Mass | 3.11±0.11[7]M☉ |
| Luminosity | 190[7]L☉ |
| Surface gravity(logg) | 3.4[4]cgs |
| Temperature | 9,250[4]K |
| Rotational velocity(vsini) | 4±1[4]km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Theta Virginis(θ Vir, θ Virginis) is amultiple star systemin thezodiacconstellation ofVirgo.Based uponparallaxmeasurements, it is about 320light yearsfrom the Sun. The three[9]stars in this system have a combinedapparent visual magnitudeof 4.37,[2]bright enough to be seen with the naked eye.
The primary component, Theta Virginis Aa, is a white-huedA-type main sequence starwith astellar classificationof A1Vs.[4]It is part of aspectroscopic binary[10]whose components, Aa and Ab, have visual magnitudes of +4.49 and +6.83 respectively. The system has anorbital periodof about 33.04 years with aneccentricityof 0.9.[3]The brighter member of this pair showsphotometricandradial velocityperiodicities with a cycle time of 0.7 days, which may indicate its rotation period.[11]
The inner pair is orbited by the 9.4 magnitude B component, at anangular separationof 7.1arcseconds.A fourth component C, 69.6 arcseconds away, has an apparent magnitude of 10.4.[3]However, component C is an optical companion: it is physically unrelated and only appears close in the sky.[9]
References
[edit]- ^abcdevan Leeuwen, F. (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,S2CID18759600.
- ^abcdMermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)",Catalogue of Eggen's UBV Data,SIMBAD,Bibcode:1986EgUBV........0M.
- ^abcdEggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems",Monthly Notices of the Royal Astronomical Society,389(2): 869–879,arXiv:0806.2878,Bibcode:2008MNRAS.389..869E,doi:10.1111/j.1365-2966.2008.13596.x,S2CID14878976.
- ^abcdeLandstreet, J. D.; et al. (September 2009), "Atmospheric velocity fields in tepid main sequence stars",Astronomy and Astrophysics,503(3): 973–984,arXiv:0906.3824,Bibcode:2009A&A...503..973L,doi:10.1051/0004-6361/200912083,S2CID53423301.
- ^Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities",Carnegie Institute Washington D.C. Publication,Carnegie Institute of Washington, D.C.,Bibcode:1953GCRV..C......0W.
- ^Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation",Astronomy Letters,38(5): 331,arXiv:1108.4971,Bibcode:2012AstL...38..331A,doi:10.1134/S1063773712050015,S2CID119257644.
- ^abZorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities",Astronomy & Astrophysics,537:A120,arXiv:1201.2052,Bibcode:2012A&A...537A.120Z,doi:10.1051/0004-6361/201117691,S2CID55586789.
- ^"tet Vir".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2016-09-05.
{{cite web}}:CS1 maint: postscript (link) - ^abTokovinin, Andrei (2018)."The Updated Multiple Star Catalog".The Astrophysical Journal Supplement Series.235(1): 6.arXiv:1712.04750.Bibcode:2018ApJS..235....6T.doi:10.3847/1538-4365/aaa1a5.S2CID119047709.
- ^Adelman, Saul J. (November 1997), "On the possible variability of the main sequence A stars theta Virginis and 109 Virginis",Astronomy & Astrophysics Supplement Series,125(3): 497–499,Bibcode:1997A&AS..125..497A,doi:10.1051/aas:1997105.
- ^Scholz, G.; et al. (September 1998), "Spectroscopic and photometric investigations of MAIA candidate stars",Astronomy and Astrophysics,337:447–459,Bibcode:1998A&A...337..447S.
External links
[edit]- Kaler, James B.,"Theta Virginis",Stars,University of Illinois,retrieved2016-09-08.
- Plotner, Tammy; Vogt, Ken (2009),The Night Sky Companion: A Yearly Guide to Sky-Watching 2009,The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 172,ISBN978-0387795096.
