Theta Virginis

θ Virginis
Location of θ Virginis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Virgo
Right ascension 13h 09m 56.99067s[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−B color index +0.00[2]
B−V color 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 ± 1.09 mas[1]
Distanceapprox. 320 ly
(approx. 100 pc)
Absolute magnitude (MV)−0.52[6]
Details
θ Vir Aa
Mass3.11±0.11[7] M☉
Luminosity190[7] L☉
Surface gravity (log g)3.4[4] cgs
Temperature9,250[4] K
Rotational velocity (v sin i)4±1[4] km/s
Other designations
51 Virginis, θ Vir, BD−04°3430, FK5 490, HD 114330, HIP 64238, HR 4963, SAO 139189.[8]
Database references
SIMBADdata

Theta Virginis (θ Vir, θ Virginis) is a multiple star system in the zodiac constellation of Virgo. Based upon parallax measurements, it is about 320 light years from the Sun. The three[9] stars in this system have a combined apparent visual magnitude of 4.37,[2] bright enough to be seen with the naked eye.

The primary component, Theta Virginis Aa, is a white-hued A-type main sequence star with a stellar classification of A1Vs.[4] It is part of a spectroscopic binary[10] whose components, Aa and Ab, have visual magnitudes of +4.49 and +6.83 respectively. The system has an orbital period of about 33.04 years with an eccentricity of 0.9.[3] The brighter member of this pair shows photometric and radial velocity periodicities 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 an angular separation of 7.1 arcseconds. 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]

  1. ^ a b c d e Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference Landstreet2009 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gcrv1953 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference aaa537_A120 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ a b Tokovinin, 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. S2CID 119047709.
  10. ^ Cite error: The named reference Adelman1997 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Scholz1998 was invoked but never defined (see the help page).