Epsilon Columbae, Latinized from ε Columbae, is a star in the southern constellation of Columba. It is visible to the naked eye, having an apparent visual magnitude of 3.87.[2] Based upon an annual parallax shift of 12.46 mas,[1] it is located approximately 262 light years distant from the Sun. The star is drifting closer with a radial velocity of −5 km/s.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba |
| Right ascension | 05h 31m 12.74899s[1] |
| Declination | −35° 28′ 13.8605″[1] |
| Apparent magnitude (V) | 3.87[2] |
| Characteristics | |
| Spectral type | K1 II/III[3] or K1 IIIa[4] |
| U−B color index | +1.08[2] |
| B−V color index | +1.14[2] |
| Astrometry | |
| Radial velocity (Rv) | −4.9[5] km/s |
| Proper motion (μ) | RA: +26.421[1] mas/yr Dec.: −30.085[1] mas/yr |
| Parallax (π) | 12.4610 ± 0.2423 mas[1] |
| Distance | 262 ± 5 ly (80 ± 2 pc) |
| Absolute magnitude (MV) | −0.67[6] |
| Details | |
| Mass | 2.47[7] M☉ |
| Radius | 25.2+3.1 −2.0[1] R☉ |
| Luminosity | 251.2±5.6[1] L☉ |
| Surface gravity (log g) | 2.05[4] cgs |
| Temperature | 4,575+195 −260[1] K |
| Metallicity [Fe/H] | −0.03[4] dex |
| Age | 1.53[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an orange-hued[9] K-type giant star with a stellar classification of K1 II/III.[3] 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[1] 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.[1] It has a peculiar velocity of 30.0±3.9 km/s, making it a candidate runaway star system.[10] Based upon changes in the star's movement, it has an orbiting stellar companion of unknown type.[11]
References
edit- ^ a b c d e f g h i j k 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.
- ^ a b c d 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.
- ^ a b 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.
- ^ a b c 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.
- ^ a b 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.
- ^ 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, S2CID 119257644.
- ^ a b c d 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.
- ^ "eps Col". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-12-22.
{{cite web}}: CS1 maint: postscript (link) - ^ 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.
- ^ 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.
- ^ 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.