Kappa Arae

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Kappa Arae
Diagram showing star positions and boundaries of the Ara constellation and its surroundings
Cercle rouge 100%.svg

The location of κ Arae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ara
Right ascension 17h 26m 00.04169s[1]
Declination –50° 38′ 00.6417″[1]
Apparent magnitude (V) 5.21[2]
Characteristics
Spectral type G8 III[3]
B−V color index +1.05[2]
Astrometry
Radial velocity (Rv) +17.3[4] km/s
Proper motion (μ) RA: +13.45[1] mas/yr
Dec.: +8.36[1] mas/yr
Parallax (π) 7.16 ± 0.40[1] mas
Distance 460 ± 30 ly
(140 ± 8 pc)
Absolute magnitude (MV) –0.58[5]
Details
Radius 14[6] R
Surface gravity (log g) 2.3[5] cgs
Temperature 4,950[5] K
Metallicity [Fe/H] –0.3[5] dex
Other designations
CD –50° 11269, HD 157457, HIP 85312, HR 6468, SAO 244734.[7]

Kappa Arae (κ Ara, κ Arae) is the Bayer designation for a single[8] star in the southern constellation of Ara. Based upon parallax measurements, it is approximately 460 light-years (140 parsecs) distant from Earth, give or take a 30 light-year margin of error.[1] With an apparent visual magnitude of 5.21,[2] this star is faintly visible to the naked eye.

This is a giant star with a stellar classification of G8 III;[3] its outer envelope has expanded to about 14 times the radius of the Sun.[6] It is radiating energy into space at an effective temperature of 4,950 K.[5] This is hot enough for it to shine with the golden-hued glow of a G-type star.[9]

It has two 14th magnitude optical companions that are at an angular distance of 25 and 30 arcseconds.[citation needed]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (November 2007), Validation of the new Hipparcos reduction, Astronomy and Astrophysics 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c 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, Bibcode:1968MNSSA..27...11C. 
  3. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H. 
  4. ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard,, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E. 
  5. ^ a b c d e Jasniewicz, G. et al. (February 1999), Late-type giants with infrared excess. I. Lithium abundances, Astronomy and Astrophysics 342: 831–838, Bibcode:1999A&A...342..831J 
  6. ^ a b Pasinetti Fracassini, L. E. et al. (February 2001), Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics, Astronomy and Astrophysics 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451. 
  7. ^ kap Ara -- Star in double system, SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), retrieved 2010-07-30. 
  8. ^ 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. 
  9. ^ The Colour of Stars, Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16. 

External links[edit]