Astronomy:Kappa Arae

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Short description: Star in the constellation Ara
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
Equinox J2000.0]] (ICRS)
Constellation Ara
Right ascension  17h 26m 00.04169s[1]
Declination –50° 38′ 00.6417″[1]
Apparent magnitude (V) 5.21[2]
Spectral type G8 III[3]
B−V color index +1.05[2]
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
Distance460 ± 30 ly
(140 ± 8 pc)
Absolute magnitude (MV)–0.58[5]
Radius14[6] R
Surface gravity (log g)2.3[5] cgs
Temperature4,950[5] K
Metallicity [Fe/H]–0.3[5] dex
Other designations
CD–50° 11269, HD 157457, HIP 85312, HR 6468, SAO 244734.[7]
Database references

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.


  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 (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, 
  4. Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". in Batten, Alan Henry; Heard, John Frederick. IAU Symposium no. 30. 30. University of Toronto: International Astronomical Union. p. 57. Bibcode1967IAUS...30...57E. 
  5. 5.0 5.1 5.2 5.3 5.4 Jasniewicz, G. et al. (February 1999), "Late-type giants with infrared excess. I. Lithium abundances", Astronomy and Astrophysics 342: 831–838, Bibcode1999A&A...342..831J 
  6. 6.0 6.1 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 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  7. "kap Ara". SIMBAD. Centre de données astronomiques de Strasbourg. 
  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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  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