Astronomy:Kappa Aurigae

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Short description: G-type giant star in the constellation Auriga
κ Aurigae
Auriga constellation map.svg
Red circle.svg
Location of κ Aurigae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Auriga
Right ascension  06h 15m 22.68906s[1]
Declination +29° 29′ 53.0760″[1]
Apparent magnitude (V) 4.335[2]
Characteristics
Evolutionary stage horizontal branch[3]
Spectral type G8.5 IIIb[4]
U−B color index +0.812[2]
B−V color index +1.023[2]
R−I color index 0.54
Astrometry
Radial velocity (Rv)+20.69 ± 0.15[5] km/s
Proper motion (μ) RA: −70.88[1] mas/yr
Dec.: −261.42[1] mas/yr
Parallax (π)18.43 ± 0.23[1] mas
Distance177 ± 2 ly
(54.3 ± 0.7 pc)
Absolute magnitude (MV)+0.65[6]
Details
Mass1.25[7] M
Radius11[5] R
Luminosity54[5] L
Surface gravity (log g)2.7[5] cgs
Temperature4,732[5] K
Metallicity [Fe/H]−0.33[5] dex
Rotational velocity (v sin i)2.5[5] km/s
Age5.59[7] Gyr
Other designations
κ Aur, 44 Aurigae, BD+29°1154, FK5 1168, HD 43039, HIP 29696, HR 2219, SAO 78143, 2MASS J06152269+2929535, Gaia DR2 3436911415279548032[8]
Database references
SIMBADdata

Kappa Aurigae, Latinised from κ Aurigae, is the Bayer designation for a star in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.3.[2] Based upon an annual parallax shift of 18.43 mas,[1] it is approximately 177 light-years (54 parsecs) distant from Earth.

This is an evolved giant star with a stellar classification of G8.5 IIIb.[4] It is a red clump star, which means it is towards the cool end of the horizontal branch and is generating energy through the fusion of helium at its core.[3] Kappa Aurigae has expanded to 11 times the radius of the Sun and shines with 54 times the Sun's luminosity. This energy is radiated into outer space from the outer envelope at an effective temperature of 4,732 K.[5] At this heat, the star glows with the orange hue of a G-type star.[9]

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 2.3 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society 172 (3): 667–679, doi:10.1093/mnras/172.3.667, Bibcode1975MNRAS.172..667J. 
  3. 3.0 3.1 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode2000ApJ...539..732A. 
  4. 4.0 4.1 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. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Massarotti, Alessandro et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal 135 (1): 209–231, doi:10.1088/0004-6256/135/1/209, Bibcode2008AJ....135..209M. 
  6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode2015AJ....150...88L. 
  8. "* kap Aur". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+kap+Aur. 
  9. "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16. 

References