Astronomy:HD 77912

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Short description: Star in the constellation Lynx
HD 77912
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lynx
Right ascension  09h 06m 31.76860s[1]
Declination +38° 27′ 07.9756″[1]
Apparent magnitude (V) 4.56[2]
Characteristics
Spectral type G7 II Ba0.2[3]
B−V color index 1.037±0.003[4]
Astrometry
Radial velocity (Rv)+16.6±0.2[4] km/s
Proper motion (μ) RA: −27.653[1] mas/yr
Dec.: −15.055[1] mas/yr
Parallax (π)5.0045 ± 0.1977[1] mas
Distance650 ± 30 ly
(200 ± 8 pc)
Absolute magnitude (MV)−1.46±0.093[5]
Details
Mass4.60[6] M
Radius33±5[2] R
Luminosity1,168.35[4] L
Surface gravity (log g)1.75[6] cgs
Temperature4,899[6] K
Metallicity [Fe/H]−0.14[6] dex
Other designations
BD+39°2200, FK5 1237, HD 77912, HIP 44700, HR 3612, SAO 61254[7]
Database references
SIMBADdata

HD 77912 is a single[8] star in the northern constellation of Lynx. It is visible to the naked eye with an apparent visual magnitude of 4.56.[2] The star is located 650 light years from the Sun, as determined from its annual parallax shift of 5.0 mas.[1] It is moving further away with a heliocentric radial velocity of +16.6 km/s.[4] HD 77912 has a peculiar velocity of 23.1+2.9
−1.1
 km/s
, which may mark it as a runaway star.[9]

The stellar classification of HD 77912 is G7 II Ba0.2,[3] indicating it is a bright giant with a mild overabundance of barium. It has 4.6[6] times the mass of the Sun and has expanded to 33[2] times the Sun's radius. The star is radiating 1,168[4] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,899 K.[6]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 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. 
  2. 2.0 2.1 2.2 2.3 Van Belle, G. T. et al. (2009), "Supergiant temperatures and linear radii from near-infrared interferometry", Monthly Notices of the Royal Astronomical Society 394 (4): 1925, doi:10.1111/j.1365-2966.2008.14146.x, Bibcode2009MNRAS.394.1925V. 
  3. 3.0 3.1 Lu, Phillip K. (1991), "Taxonomy of barium stars", Astronomical Journal 101: 2229, doi:10.1086/115845, Bibcode1991AJ....101.2229L. 
  4. 4.0 4.1 4.2 4.3 4.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  5. Park, Sunkyung et al. (2013), "Wilson-Bappu Effect: Extended to Surface Gravity", The Astronomical Journal 146 (4): 73, doi:10.1088/0004-6256/146/4/73, Bibcode2013AJ....146...73P. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Liu, Y. J. et al. (April 2014), "The Lithium Abundances of a Large Sample of Red Giants", The Astrophysical Journal 785 (2): 12, doi:10.1088/0004-637X/785/2/94, 94, Bibcode2014ApJ...785...94L. 
  7. "HD 77912". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+77912. 
  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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  9. Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T.