Astronomy:Epsilon Columbae

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Short description: Star in the constellation Columba
ε Columbae
Location of ε Columbae (circled in red)
Observation data
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[2] mas/yr
Dec.: −32.416[2] mas/yr
Parallax (π)11.7300 ± 0.1374[2] mas
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

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]

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

  1. 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940.  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 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. 
  4. 4.0 4.1 Houk, Nancy (1982), Michigan catalogue of two-dimensional spectral types for the HD stars, 3, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1982mcts.book.....H. 
  5. 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. 
  6. 6.0 6.1 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode2006AstL...32..759G. 
  7. 7.0 7.1 7.2 7.3 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode2015AJ....150...88L. 
  8. 8.0 8.1 8.2 8.3 8.4 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.
  9. 9.0 9.1 9.2 Soubiran, C. et al. (July 1, 2022), "Assessment of [Fe/H] determinations for FGK stars in spectroscopic surveys", Astronomy and Astrophysics 663: A4, doi:10.1051/0004-6361/202142409, ISSN 0004-6361, Bibcode2022A&A...663A...4S. 
  10. "eps Col". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=eps+Col. 
  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, https://books.google.com/books?id=3vxLNPNHOcwC&pg=PA260. 
  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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T. 
  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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E.