Epsilon Columbae

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]

ε Columbae

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
ε Col, CD−35°2348, FK5 2413, HD 36597, HIP 25859, HR 1862, SAO 195924[8]
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]