Astronomy:Chi Leonis

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Short description: Double star system in the constellation Leo
χ Leonis
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Leo
Right ascension  11h 05m 01.02754s[1]
Declination +07° 20′ 09.6235″[1]
Apparent magnitude (V) 4.63[2]
Characteristics
Spectral type F2III-IVv[3]
U−B color index +0.06[2]
B−V color index +0.33[2]
Astrometry
Radial velocity (Rv)+4.7[4] km/s
Proper motion (μ) RA: −344.28[1] mas/yr
Dec.: −47.65[1] mas/yr
Parallax (π)34.49 ± 0.20[1] mas
Distance94.6 ± 0.5 ly
(29.0 ± 0.2 pc)
Absolute magnitude (MV)+2.31[5]
Details
Mass1.62[6] M
Radius1.99[7] R
Luminosity9.9[5] L
Surface gravity (log g)4.02[6] cgs
Temperature7022±80[6] K
Metallicity [Fe/H]+0.03[6] dex
Rotational velocity (v sin i)25±1[3] km/s
Age1.40[6] Gyr
Other designations
χ Leo, 63 Leo, BD+08°2455, FK5 418, HD 96097, HIP 54182, HR 4310, SAO 118648[8]
Database references
SIMBADdata

Chi Leonis, Latinized from χ Leonis, is a double star in the constellation Leo. It is visible to the naked eye with an apparent visual magnitude of 4.63.[2] The distance to this star, as determined using parallax measurements,[1] is around 95 light years. It has an annual proper motion of 346 mas.[9]

This is most likely a binary star system.[10] The primary component is an evolved, F-type giant star with a stellar classification of F2III-IVv.[3] It has an estimated 162%[6] of the Sun's mass and nearly twice the Sun's radius.[7] The companion is a magnitude 11.0 star at an angular separation of 4.1 along a position angle of 264°, as of 1990.[11]

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  2. 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode1986EgUBV........0M. 
  3. 3.0 3.1 3.2 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. 
  4. Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Carnegie Institute of Washington, D.C.), Bibcode1953GCRV..C......0W. 
  5. 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode2011A&A...530A.138C. 
  7. 7.0 7.1 Rachford, Brian L.; Foight, Dillon R. (June 2009), "Chromospheric Variability in Early F-Type Stars", The Astrophysical Journal 698 (1): 786–802, doi:10.1088/0004-637X/698/1/786, Bibcode2009ApJ...698..786R. 
  8. "* chi Leo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+chi+Leo. 
  9. Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal 129 (3): 1483–1522, doi:10.1086/427854, Bibcode2005AJ....129.1483L. 
  10. 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. 
  11. Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode2001AJ....122.3466M.