Astronomy:Kappa Arietis

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Short description: Binary star system in the constellation Aries
Kappa Arietis
Aries constellation map.svg
Red circle.svg
Location of κ Arietis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aries
Right ascension  02h 06m 33.92497s[1]
Declination +22° 38′ 53.9476″[1]
Apparent magnitude (V) 5.02[2]
Characteristics
Spectral type A2m[3]
U−B color index +0.11[2]
B−V color index +0.12[2]
Astrometry
Radial velocity (Rv)+11.5[4] km/s
Proper motion (μ) RA: +20.348[1] mas/yr
Dec.: −35.671[1] mas/yr
Parallax (π)18.0292 ± 0.3092[1] mas
Distance181 ± 3 ly
(55.5 ± 1.0 pc)
Absolute magnitude (MV)1.30[3]
Orbit[5]
Period (P)15.2938 d
Eccentricity (e)0.61
Periastron epoch (T)2,421,844.121 JD
Argument of periastron (ω)
(secondary)
358.3°
Semi-amplitude (K1)
(primary)
34.5 km/s
Semi-amplitude (K2)
(secondary)
35.4 km/s
Details
Luminosity25[3] L
Surface gravity (log g)4.0[6] cgs
Temperature8,700[6] K
Metallicity [Fe/H]+0.18[6] dex
Rotational velocity (v sin i)18[7] km/s
Other designations
κ Ari, 12 Arietis, BD+21°279, HD 12869, HIP 9836, HR 613, SAO 75146[8]
Database references
SIMBADdata

Kappa Arietis, Latinized from κ Arietis, is the Bayer designation for a binary star in the northern constellation of Aries. The combined apparent visual magnitude of the pair is 5.02,[2] making the system bright enough for it to be dimly visible to the naked eye as a white-hued point of light. It is located approximately 181 light-years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +11.5 km/s.[4]

The binary nature of this system was announced in 1918 by Lick Observatory. It is a double-lined spectroscopic binary with an orbital period of 15.3 days and an eccentricity of 0.61.[5] Both components displaying the spectral properties of an Am, or metallic-lined star. They have nearly the same brightness and their mass ratio is 1.03; very close to equal.[6]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Mendoza, E. E. et al. (June 1978), "UBVRI photometry of 225 AM stars", Astronomical Journal 83: 606–614, doi:10.1086/112242, Bibcode1978AJ.....83..606M. 
  3. 3.0 3.1 3.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  4. 4.0 4.1 Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington), Bibcode1953GCRV..C......0W. 
  5. 5.0 5.1 Jones, Rebecca B. (1931), "The orbit of the spectroscopic binary κ Arietis", Lick Observatory Bulletin (Berkeley: University of California Press) 433: 117–122, doi:10.5479/ADS/bib/1931LicOB.15.117J, Bibcode1931LicOB..15..117J. 
  6. 6.0 6.1 6.2 6.3 Mitton, J. (January 1977), "Spectroscopic observations and curve-of-growth analyses of the four A stars omicron Peg, beta Ari, kappa Ari and 32 Vir", Astronomy and Astrophysics Supplement Series 27: 35–46, Bibcode1977A&AS...27...35M. 
  7. Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode2002A&A...393..897R. 
  8. "kap Ari". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=kap+Ari. 

External links