Epsilon Columbae is a star in the southern constellation of Columba. Its name is a Bayer designation that is Latinized from ε Columbae, and abbreviated Epsilon Col or ε Col. This star is visible to the naked eye, having an apparent visual magnitude of 3.87.[3] Based upon an annual parallax shift of 11.73 mas,[8] it is located approximately 278 light-years (85.3 pc) distant from the Sun. The star is drifting closer with a radial velocity of −5 km/s.[6]

ε Columbae
Location of ε Columbae (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Columba[1]
Right ascension 05h 31m 12.747s[2]
Declination −35° 28 13.82[2]
Apparent magnitude (V) 3.87[3]
Characteristics
Spectral type K1 II/III[4] or K1 IIIa[5]
U−B color index +1.08[3]
B−V color index +1.14[3]
Astrometry
Radial velocity (Rv)−4.9±0.7[6] km/s
Proper motion (μ) RA: +27.627 mas/yr[2]
Dec.: −32.416 mas/yr[2]
Parallax (π)11.7300±0.1374 mas[2]
Distance278 ± 3 ly
(85.3 ± 1.0 pc)
Absolute magnitude (MV)−0.67[1]
Details
Mass2.47[7] M
Radius25.2+3.1
−2.0
[8] R
Luminosity251.2±5.6[8] L
Surface gravity (log g)1.76±0.10[9] cgs
Temperature4,573±50[9] K
Metallicity [Fe/H]−0.07±0.10[9] dex
Age1.53[7] Gyr
Other designations
ε Col, CD−35°2348, FK5 2413, HD 36597, HIP 25859, HR 1862, SAO 195924[10]
Database references
SIMBADdata

This is an orange-hued[11] K-type giant star with a stellar classification of K1 II/III.[4] At the age of 1.5[7] billion years old, it has exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. Epsilon Columbae has 2.5[7] times the mass and 25[8] times the radius of the Sun. The star radiates 251 times the solar luminosity from its enlarged photosphere at an effective temperature of 4,575 K.[8] It has a peculiar velocity of 30.0±3.9 km/s, making it a candidate runaway star system.[12] Based upon changes in the star's movement, it has an orbiting stellar companion of unknown type.[13]

References

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  1. 1 2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  4. 1 2 Houk, Nancy (1982), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
  5. Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
  6. 1 2 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
  7. 1 2 3 4 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.
  8. 1 2 3 4 5 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.
  9. 1 2 3 Soubiran, C.; et al. (July 1, 2022), "Assessment of [Fe/H] determinations for FGK stars in spectroscopic surveys", Astronomy and Astrophysics, 663: A4, arXiv:2112.07545, Bibcode:2022A&A...663A...4S, doi:10.1051/0004-6361/202142409, ISSN 0004-6361.
  10. "eps Col", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2016-12-22.
  11. Kambic, Bojan (2009), Viewing the Constellations with Binoculars: 250+ Wonderful Sky Objects to See and Explore, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 260, ISBN 978-0387853550.
  12. Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  13. 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.