74 Virginis

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74 Virginis
Virgo constellation map.svg
Red circle.svg
Location of 74 Virginis (circled in red)
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Virgo
Right ascension 13h 31m 57.88506s [1]
Declination −06° 15 20.9419 [1]
Apparent magnitude  (V)4.69±0.01 [2]
Characteristics
Spectral type M2.5 III [3]
B−V color index 1.606±0.035
Astrometry
Radial velocity (Rv)+18.71±0.15 [4] km/s
Proper motion (μ)RA: −103.94 [1] mas/yr
Dec.: −43.87 [1] mas/yr
Parallax (π)8.16±0.19  mas [1]
Distance 400 ± 9  ly
(123 ± 3  pc)
Absolute magnitude  (MV)−0.76 [5]
Details [2]
Mass 1.40±0.12  M
Radius 78.38+1.98
−1.90
  R
Luminosity 831.5±56.8  L
Temperature 3,500±46  K
Metallicity [Fe/H]0.00  dex
Age 2.90±0.68  Gyr
Other designations
Apamvatsa, l Vir, 74 Vir, NSV 6297, BD−05°3714, FK5 3079, HD 117675, HIP 66006, HR 5095, SAO 139390 [6]
Database references
SIMBAD data

74 Virginis, also named Apamvatsa, [7] is a single [8] star in the zodiac constellation of Virgo. [6] It is visible to the naked eye as a faint red-hued star with an apparent visual magnitude of 4.69. [2] The star is positioned near the ecliptic and thus is subject to lunar occultations. [9] The measured annual parallax of 8.16  mas [1] provides a distance estimate of around 400  light-years from the Sun. At that range, the visual magnitude of the star is diminished by an extinction of 0.46±0.02 due to interstellar dust. [2] It is moving further from the Earth with a heliocentric radial velocity of +19 km/s. [4]

This is an aging red giant star with a stellar classification of M2.5 III, [3] which indicates it has exhausted the hydrogen at its core and evolved away from the main sequence. It is a suspected variable star that may vary in brightness with an amplitude of 0.07 in magnitude. [10] The star is roughly 2.9 billion years old with 1.4 times the mass of the Sun and has expanded to around 78 times the Sun's radius. 74 Virginis is radiating 832 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,500 K. [2]

In traditional Indian astronomy, the star Āpaṃvatsa ("calf of the waters") is described as being 5° to the north of Chitra (Spica), as first attested in the text Sūryasiddhānta . This position corresponds to 74 Virginis. [11] The IAU Working Group on Star Names approved the name Apamvatsa for this star on 16 October 2025 and it is now so entered in the IAU Catalog of Star Names. [7]

References

  1. 1 2 3 4 5 6 van 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, S2CID   18759600.
  2. 1 2 3 4 5 Baines, Ellyn K.; et al. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal, 155 (1), 30, arXiv: 1712.08109 , Bibcode:2018AJ....155...30B, doi: 10.3847/1538-3881/aa9d8b , S2CID   119427037.
  3. 1 2 Keenan, Philip C; McNeil, Raymond C (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373
  4. 1 2 Famaey, B.; et al. (2009), "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics, 498 (2): 627–640, arXiv: 0901.0934 , Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698, S2CID   18739721.
  5. 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, S2CID   119257644.
  6. 1 2 "74 Vir". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-02-13.
  7. 1 2 "IAU-Catalog of Star Names – exopla.net" . Retrieved 2025-10-17.
  8. Eggleton, P. P.; Tokovinin, A. A. (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 , S2CID   14878976.
  9. Antal, M. (1962), "Observations of occultations at the Observatory Skalnaté Pleso in the year 1961", Bulletin of the Astronomical Institute of Czechoslovakia, 13: 164, Bibcode:1962BAICz..13..164A.
  10. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID   125853869.
  11. "Āpaṃvatsa (अपऻऺवत्स)". All Skies Encyclopaedia. IAU Working Group on Star Names . Retrieved 15 October 2025.