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]

HD 77912
Observation data
Epoch J2000      Equinox J2000
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 mas[1]
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

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

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  1. ^ a b c d e f 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.
  2. ^ a b c d 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, arXiv:0811.4239, Bibcode:2009MNRAS.394.1925V, doi:10.1111/j.1365-2966.2008.14146.x, S2CID 118372600.
  3. ^ a b Lu, Phillip K. (1991), "Taxonomy of barium stars", Astronomical Journal, 101: 2229, Bibcode:1991AJ....101.2229L, doi:10.1086/115845.
  4. ^ a b c d e 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.
  5. ^ Park, Sunkyung; et al. (2013), "Wilson-Bappu Effect: Extended to Surface Gravity", The Astronomical Journal, 146 (4): 73, arXiv:1307.0592, Bibcode:2013AJ....146...73P, doi:10.1088/0004-6256/146/4/73, S2CID 119187733.
  6. ^ a b c d e f Liu, Y. J.; et al. (April 2014), "The Lithium Abundances of a Large Sample of Red Giants", The Astrophysical Journal, 785 (2): 12, arXiv:1404.1687, Bibcode:2014ApJ...785...94L, doi:10.1088/0004-637X/785/2/94, S2CID 119226316, 94.
  7. ^ "HD 77912". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-30.
  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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.