epsilon Columbae
{{Short description|Star in the constellation Columba}}
{{Starbox begin
| name = ε Columbae
}}
{{Starbox observe
| epoch = J2000.0
| constell = Columba
| dec = {{DEC|−35|28|13.8605}}
}}
{{Starbox character
| class = K1 II/III or K1 IIIa
| r-i =
| variable =
}}
{{Starbox astrometry
| parallax = 12.4610
| p_error = 0.2423
}}
{{Starbox detail
| radius = {{val|25.2|3.1|2.0}}
| luminosity = {{val|251.2|5.6}}
| temperature = {{val|4575|195|260|fmt=commas}}
| rotational_velocity =
| rotation =
}}
{{Starbox catalog
| names = {{odlist | B=ε Col | CD=−35° 2348 | FK5=2413 | HD=36597 | HIP=25859 | HR=1862 | SAO=195924 }}
}}
{{Starbox reference
| Simbad = eps+Col
}}
{{starbox end}}
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. Based upon an annual parallax shift of {{val|12.46|ul=mas}}, it is located approximately 262 light years distant from the Sun. The star is drifting closer with a radial velocity of −5 km/s.
This is an orange-hued K-type giant star with a stellar classification of K1 II/III. At the age of 1.5 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 times the mass and 25 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. It has a peculiar velocity of {{Val|30.0|3.9|u=km/s}}, making it a candidate runaway star system. Based upon changes in the star's movement, it has an orbiting stellar companion of unknown type.
References
{{reflist|refs=
{{Cite Gaia DR2|4822106194361724800}}
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| url=https://books.google.com/books?id=3vxLNPNHOcwC&pg=PA260 }}
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| doi=10.1088/0004-6256/150/3/88 | bibcode=2015AJ....150...88L
|arxiv = 1507.01466 | s2cid=118505114
}}
| last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A.
| title=A catalogue of multiplicity among bright stellar systems
| journal=Monthly Notices of the Royal Astronomical Society
| volume=389 | issue=2 | pages=869–879 | date=September 2008
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| arxiv=0806.2878 | s2cid=14878976 | postscript=. }}
| last=Wilson | first=Ralph Elmer | date=1953
| title=General Catalogue of Stellar Radial Velocities
| journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington | postscript=.
| location=Washington | bibcode=1953GCRV..C......0W }}
| last1=Houk | first1=Nancy
| title=Michigan catalogue of two-dimensional spectral types for the HD stars
| volume=3 | publication-place=Ann Arbor
| publisher=Dept. of Astronomy, University of Michigan
| year=1982 | bibcode=1982mcts.book.....H | postscript=. }}
| last1=Johnson | first1=H. L. | last2=Iriarte | first2=B.
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| title=UBVRIJKL photometry of the bright stars
| journal=Communications of the Lunar and Planetary Laboratory
| volume=4 | issue=99 | year=1966 | page=99 | display-authors=1
| bibcode=1966CoLPL...4...99J | postscript=. }}
| title=Abundances in the Local Region. I. G and K Giants
| last=Luck | first=R. Earle
| journal=The Astronomical Journal
| volume=150 | issue=3 | id=88 | pages=23 | date=September 2015
| doi=10.1088/0004-6256/150/3/88 | bibcode=2015AJ....150...88L
| arxiv=1507.01466 | s2cid=118505114 | postscript=. }}
| title=eps Col
| accessdate=2016-12-22 | postscript=. }}
}}
{{Stars of Columba|state=collapsed}}
{{DEFAULTSORT:Epsilon Columbae}}
Category:Columba (constellation)