Astronomy:Beta Horologii

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Short description: Star in the constellation Horologium
β Horologii
Observation data
Equinox J2000.0]] (ICRS)
Constellation Horologium
Right ascension  02h 58m 47.79642s[1]
Declination −64° 04′ 16.6250″[1]
Apparent magnitude (V) 4.979[2]
Characteristics
Spectral type A3/5 III(m)[3]
U−B color index +0.15[4]
B−V color index +0.13[4]
R−I color index +0.05[4]
Astrometry
Radial velocity (Rv)+23.6±2.8[5] km/s
Proper motion (μ) RA: 22.074 ± 0.294[6] mas/yr
Dec.: 5.825 ± 0.287[6] mas/yr
Parallax (π)10.4568 ± 0.1427[6] mas
Distance312 ± 4 ly
(96 ± 1 pc)
Absolute magnitude (MV)+0.20[7]
Details
Radius1.40[8] R
Luminosity63[9] L
Temperature8,303[9] K
Rotational velocity (v sin i)115[10] km/s
Other designations
β Hor, CPD−64° 215, FK5 2212, GC 3611, HD 18866, HIP 13884, HR 909, SAO 248701, PPM 353263[2]
Database references
SIMBADdata

Beta Horologii, Latinized from β Horologii, is the third-brightest star in the southern constellation of Horologium. It is faintly visible to the naked eye with an apparent visual magnitude of 4.98.[2] Based upon an annual parallax shift of 11.07 mas as seen from Earth,[2] it is located about 295 light years from the Sun. The star is moving away with a radial velocity of +24 km/s.[5]

This is a solitary,[11] A-type giant with a stellar classification of A3/5 III(m).[3] It is a suspected chemically peculiar star of the metallic-line type.[12] Beta Horologii has a relatively high rate of spin with a projected rotational velocity of 115 km/s, giving it an oblate shape with an equatorial bulge that is an estimated 10% wider compared to the polar radius.[10] It has about 1.40[8] times the radius of the Sun and is radiating 63[9] times the Sun's luminosity from its photosphere at an effective temperature of 8,303 K.[9]

References

  1. 1.0 1.1 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 "bet hor". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=bet+hor. 
  3. 3.0 3.1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode1978mcts.book.....H. 
  4. 4.0 4.1 4.2 HR 909, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 18, 2008.
  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 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.
  7. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  8. 8.0 8.1 HD 18866, database entry, Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS), 3rd edition, L. E. Pasinetti-Fracassini, L. Pastori, S. Covino, and A. Pozzi, CDS ID II/224. Accessed on line September 18, 2008.
  9. 9.0 9.1 9.2 9.3 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode2012MNRAS.427..343M. 
  10. 10.0 10.1 van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review 20 (1): 51, doi:10.1007/s00159-012-0051-2, Bibcode2012A&ARv..20...51V. 
  11. 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. 
  12. Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics 498 (3): 961–966, doi:10.1051/0004-6361/200810788, Bibcode2009A&A...498..961R, https://zenodo.org/record/890529. 

External links