Astronomy:93 Herculis

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Short description: Star in the constellation Hercules
93 Herculis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Hercules
Right ascension  18h 00m 03.41611s[1]
Declination +16° 45′ 03.2855″[1]
Apparent magnitude (V) 4.67[2]
Characteristics
Spectral type K0.5IIb[3]
B−V color index 1.254±0.007[2]
Astrometry
Radial velocity (Rv)−24.47±0.20[4] km/s
Proper motion (μ) RA: −6.878[1] mas/yr
Dec.: −9.696[1] mas/yr
Parallax (π)4.5894 ± 0.3311[1] mas
Distance710 ± 50 ly
(220 ± 20 pc)
Absolute magnitude (MV)−1.85[2]
Details
Radius50.53+1.41
−1.39
[1] R
Luminosity919±74[1] L
Surface gravity (log g)1.8[5] cgs
Temperature4,471+63
−61
[1] K
Metallicity [Fe/H]−0.22[5] dex
Other designations
93 Her, BD+16° 3335, FK5 1469, HD 164349, HIP 88128, HR 6713, SAO 103285[6]
Database references
SIMBADdata

93 Herculis is a star located around 750[1] light years away from the Sun in the northern constellation of Hercules.[6] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.67[2] The brightness of the star is diminished by an extinction of 0.21 due to interstellar dust.[7] It is moving closer to the Earth with a heliocentric radial velocity of −24.5 km/s.[4] This star, together with 95 Her, 102 Her, and 109 Her, made up the obsolete constellation Cerberus.[8]

This object has a stellar classification of K0.5IIb,[3] which indicates it is an evolved bright giant. With the supply of hydrogen at its core exhausted, the star has expanded to 51[1] times the Sun's radius. It is radiating around 919[1] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,471 K.[1] It is generally deficient in metal elements, but appears weakly enhanced in barium and other heavier elements.[5] This is a suspected barium star and hence may have a white dwarf companion in orbit.[9]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 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 2.3 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 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. 
  5. 5.0 5.1 5.2 Smith, G. R.; Harmer, D. L. (January 1982), "A differential curve-of-growth analysis of the candidate barium star 93 Her", Monthly Notices of the Royal Astronomical Society 198: 273–280, doi:10.1093/mnras/198.1.273, Bibcode1982MNRAS.198..273S. 
  6. 6.0 6.1 "93 Her". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=93+Her. 
  7. Famaey, B. et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430 (1): 165–186, doi:10.1051/0004-6361:20041272, Bibcode2005A&A...430..165F. 
  8. Ridpath, Ian, Ian Ridpath's Star Tales - Cerberus, http://www.ianridpath.com/startales/cerberus.htm, retrieved 2019-06-16. 
  9. 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.