Xi Columbae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Columba
Right ascension 05h 55m 29.91038s[1]
Declination −37° 07′ 14.3232″[1]
Apparent magnitude (V) 4.97[2]
Characteristics
Spectral type K1 III CNII[3]
B−V color index +1.096[2]
Astrometry
Radial velocity (Rv)+59.5[4] km/s
Proper motion (μ) RA: +38.020[1] mas/yr
Dec.: −23.491[1] mas/yr
Parallax (π)10.0920 ± 0.1408 mas[1]
Distance323 ± 5 ly
(99 ± 1 pc)
Absolute magnitude (MV)−0.05[5]
Orbit[5]
Period (P)1420.6 d
Semi-major axis (a)3.60 AU
Eccentricity (e)0.39
Semi-amplitude (K1)
(primary)		5.68 km/s
Details
Radius16.23+0.14
−2.27[1] R☉
Luminosity120±2[1] L☉
Surface gravity (log g)2.26[2] cgs
Temperature4,743+372
−20[1] K
Metallicity [Fe/H]+0.29[2] dex
Rotational velocity (v sin i)2.6[5] km/s
Other designations
ξ Col, CD−37°2487, HD 40176, HIP 28010, HR 2087, SAO 196316[6]
Database references
SIMBADdata

Xi Columbae is a binary star[5] system in the southern constellation of Columba. With an apparent visual magnitude of 4.97,[2] it is faintly visible to the naked eye. Based upon an annual parallax shift of 10.1 mas,[1] it is located around 323 light years from the Sun. The system is a member of the HR 1614 supergroup,[7] and is drifting further away with a radial velocity of +59.5 km/s,[4]

This is an astrometric binary[8] with an orbital period of 1,420.6 days and an eccentricity of 0.39.[5] The primary is an evolved K-type giant star with a stellar classification of K1 III CNII,[3] showing an overabundance of CN in its spectrum. The star has expanded to 16 times the radius of the Sun and is radiating 120 times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,743 K.[1] The companion has a mass of at least 59% that of the Sun.[5]

References

  1. 1 2 3 4 5 6 7 8 9 10 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. 1 2 3 4 5 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 23, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114, 88.
  3. 1 2 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
  4. 1 2 Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
  5. 1 2 3 4 5 6 Setiawan, J.; et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, 421: 241–254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1.
  6. ↑ "ksi Col -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-12-31.
  7. ↑ Eggen, Olin J. (August 1997), "The Abundance of CN, Calcium and Heavy Elements in High Velocity Stars.", The Astronomical Journal, 114: 825–836, Bibcode:1997AJ....114..825E, doi:10.1086/118516.
  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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
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