Astronomy:Kappa Capricorni

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Short description: Star in the constellation Capricornus
κ Capricorni
Capricornus constellation map.svg
Red circle.svg
Location of κ Capricorni (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Capricornus
Right ascension  21h 42m 39.50710s[1]
Declination −18° 51′ 58.7669″[1]
Apparent magnitude (V) +4.73[2]
Characteristics
Spectral type G8 III[3]
U−B color index +0.51[2]
B−V color index +0.88[2]
Astrometry
Radial velocity (Rv)−2.87±0.18[4] km/s
Proper motion (μ) RA: +145.85[1] mas/yr
Dec.: −9.50[1] mas/yr
Parallax (π)11.09 ± 0.28[1] mas
Distance294 ± 7 ly
(90 ± 2 pc)
Absolute magnitude (MV)−0.023[5]
Details[6]
Mass2.43±0.21 M
Radius13.28±0.47 R
Luminosity106.8±5.9 L
Surface gravity (log g)2.59±0.06 cgs
Temperature5,096±57 K
Metallicity [Fe/H]−0.39±0.10 dex
Rotational velocity (v sin i)0.0[4] km/s
Age1.19[7] Gyr
Other designations
κ Cap, 43 Cap, BD−19° 6152, HD 206453, HIP 107188, HR 8288, SAO 164593[8]
Database references
SIMBADdata

Kappa Capricorni (κ Cap, κ Capricorni) is a solitary[9] star in the constellation Capricornus. It is visible to the naked eye with an apparent visual magnitude of +4.73.[2] Based upon an annual parallax shift of 11.09 mas as seen from the Earth,[1] the star is located about 294 light years from the Sun.

This is a yellow-hued, evolved, G-type giant star with a stellar classification of G8 III.[3] There is a 91% probability that it is currently on the horizontal branch, rather than the red giant branch.[6] As such, it is a red clump[10] giant with an estimated 2.43 times the mass of the Sun and has expanded to 13.28 times the radius of the Sun.[6] The star is about 1.2[7] billion years old and has a projected rotational velocity that is too small to be measured.[4] It radiates 107 times the solar luminosity from its photosphere at an effective temperature of 5,096 K.[6]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 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 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 Houk, N.; Smith-Moore, M. (1988), Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars, 4, Bibcode1988mcts.book.....H. 
  4. 4.0 4.1 4.2 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. 
  5. Soubiran, C. et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics 480 (1): 91–101, doi:10.1051/0004-6361:20078788, Bibcode2008A&A...480...91S. 
  6. 6.0 6.1 6.2 6.3 Reffert, Sabine et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy and Astrophysics 574A (2): 116–129, doi:10.1051/0004-6361/201322360, Bibcode2015A&A...574A.116R.  Values are based on 91% probability it is on the horizontal branch.
  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 Cap". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=kap+Cap. 
  9. 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. 
  10. 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.