69 Virginis

69 Virginis is a single[10] star in the zodiac constellation of Virgo, located about 259 light years away. It is visible to the naked eye as a faint orange-hued star with an apparent visual magnitude of 4.76,[2] although it is a suspected variable that may range in magnitude from 4.75 down to 4.79.[11] This object is moving closer to the Earth with a heliocentric radial velocity of −13 km/s.[5] The light from this star is polarized due to intervening interstellar dust.[12]

69 Virginis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Virgo
Right ascension  13h 27m 27.16348s[1]
Declination −15° 58′ 24.8980″[1]
Apparent magnitude (V) 4.76[2]
Characteristics
Evolutionary stage horizontal branch
Spectral type K0 III-IIIb CN1.5 CH0.5[3]
U−B color index +1.06[4]
B−V color index +1.09[4]
Astrometry
Radial velocity (Rv)−12.9±0.5[5] km/s
Proper motion (μ) RA: −121.016[1] mas/yr
Dec.: +21.197[1] mas/yr
Parallax (π)12.5871 ± 0.2367[1] mas
Distance259 ± 5 ly
(79 ± 1 pc)
Absolute magnitude (MV)0.09[2]
Details[6]
Mass3.51±0.94 M☉
Radius15[7] R☉
Luminosity87.1[7] L☉
Surface gravity (log g)2.70±0.11 cgs
Temperature4,909±92 K
Metallicity [Fe/H]0.11[8] dex
Rotational velocity (v sin i)4.3[7] km/s
Age288+343
−156 Myr
Other designations
16 Vir, NSV 6253, BD+04°2604, GJ 9444, HD 116976, HIP 65639, HR 5068, SAO 157946[9]
Database references
SIMBADdata

This is an evolved K-type giant star with a stellar classification of K0 III-IIIb CN1.5 CH0.5,[3] showing overabundances of CN and CH molecules in the spectrum. It is a red clump giant, which indicates is on the horizontal branch generating energy via helium fusion at its core.[13] The star is about 288 million years old with 3.5[6] times the mass of the Sun and 15[7] times the Sun's radius. It is radiating 87[7] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,909 K.[6]

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. 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.
  3. 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. Hoffleit, Dorrit; Jaschek, Carlos (1991), "The Bright star catalogue", New Haven, Bibcode:1991bsc..book.....H
  5. de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  6. Feuillet, Diane K.; et al. (2016), "Determining Ages of APOGEE Giants with Known Distances", The Astrophysical Journal, 817 (1): 40, arXiv:1511.04088, Bibcode:2016ApJ...817...40F, doi:10.3847/0004-637x/817/1/40.
  7. Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
  8. Meléndez, J.; et al. (June 2008), "Chemical similarities between Galactic bulge and local thick disk red giant stars", Astronomy and Astrophysics, 484 (3): L21–L25, arXiv:0804.4124, Bibcode:2008A&A...484L..21M, doi:10.1051/0004-6361:200809398.
  9. "69 Vir". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-02-10.
  10. Eggleton, 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.
  11. 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.
  12. Leroy, J. L. (July 1993), "A Polarimetric Investigation on Interstellar Dust Within 50-PARSECS from the Sun", Astronomy and Astrophysics, 274 (1): 203, Bibcode:1993A&A...274..203L.
  13. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278.
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