Astronomy:69 Virginis

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Short description: Star in the constellation Virgo
69 Virginis
Observation data
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

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]

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. 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K. 
  4. 4.0 4.1 Hoffleit, Dorrit; Jaschek, Carlos (1991), "The Bright star catalogue", New Haven, Bibcode1991bsc..book.....H 
  5. 5.0 5.1 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, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  6. 6.0 6.1 6.2 Feuillet, Diane K. et al. (2016), "Determining Ages of APOGEE Giants with Known Distances", The Astrophysical Journal 817 (1): 40, doi:10.3847/0004-637x/817/1/40, Bibcode2016ApJ...817...40F. 
  7. 7.0 7.1 7.2 7.3 7.4 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, doi:10.1088/0004-6256/135/1/209, Bibcode2008AJ....135..209M. 
  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, doi:10.1051/0004-6361:200809398, Bibcode2008A&A...484L..21M. 
  9. "69 Vir". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=69+Vir. 
  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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  11. Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/s1063772917010085, Bibcode2017ARep...61...80S. 
  12. Leroy, J. L. (July 1993), "A Polarimetric Investigation on Interstellar Dust Within 50-PARSECS from the Sun", Astronomy and Astrophysics 274 (1): 203, Bibcode1993A&A...274..203L. 
  13. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode2000ApJ...539..732A.