Astronomy:HD 157819

From HandWiki
Star in the constellation Ara
HD 157819
Observation data
Equinox J2000.0]] (ICRS)
Constellation Ara
Right ascension  17h 28m 38.91416s[1]
Declination –55° 10′ 10.8720″[1]
Apparent magnitude (V) 5.94[2]
Characteristics
Spectral type G8 II-III[3]
B−V color index +1.11[2]
Astrometry
Radial velocity (Rv)–12.6 ± 0.4[4] km/s
Proper motion (μ) RA: +2.52[1] mas/yr
Dec.: -8.92[1] mas/yr
Parallax (π)3.31 ± 0.41[1] mas
Distanceapprox. 1,000 ly
(approx. 300 pc)
Absolute magnitude (MV)–2.9[5]
Other designations
HD 157819, HIP 85520, HR 6487, SAO 244770.[6]
Database references
SIMBADdata

HD 157819 is the Henry Draper Catalogue designation for a star in the southern constellation of Ara. It is faintly visible to the naked eye at an apparent visual magnitude of 5.94[2] and is approximately 1,000 light-years (310 parsecs) distant from the Earth.[1] The spectrum of this star fits a stellar classification of G8 II-III,[3] indicating it is a G-type star that is somewhere between the giant and bright giant stages of its evolution.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 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 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa 27: 11, Bibcode1968MNSSA..27...11C. 
  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. Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode2006AstL...32..759G. 
  5. Eggen, O. J. (August 1983), "The reddening, metal abundance, and luminosity of high-luminosity G-type stars", Astronomical Journal 88: 1187–1198, doi:10.1086/113409, Bibcode1983AJ.....88.1187E. 
  6. "HR 6487 -- Star in double system", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+157819, retrieved 2012-08-04. 

External links