Eta Columbae

Eta Columbae is a solitary^[8] star near the southern boundary of the constellation Columba.^[9] It is visible to the naked eye, having an apparent visual magnitude of 3.96.^[2] Based upon an annual parallax shift of 6.91 mas,^[1] it lies at a distance of roughly 472 light years from the Sun.

η Columbae

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Columba
Right ascension	05h 59m 08.80519s[1]
Declination	−42° 48′ 54.4822″[1]
Apparent magnitude (V)	3.96[2]
Characteristics
Spectral type	G8/K1 II[3] or K0 III[4]
U−B color index	+1.08[2]
B−V color index	+1.14[2]
Astrometry
Radial velocity (Rv)	+17.0[4] km/s
Proper motion (μ)	RA: +18.39[1] mas/yr Dec.: −10.87[1] mas/yr
Parallax (π)	6.91±0.12 mas[1]
Distance	472 ± 8 ly (145 ± 3 pc)
Absolute magnitude (MV)	−2.10[5]
Details[4]
Mass	3.33 M☉
Radius	38.6[6] R☉
Luminosity	708 L☉
Surface gravity (log g)	1.72 cgs
Temperature	4,620±54 K
Metallicity [Fe/H]	−0.01 dex
Other designations
η Col, CD−42°2266, FK5 229, HD 40808, HIP 28328, HR 2120, SAO 217650.[7]
Database references
SIMBAD	data

This is an orange-hued^[9] K-type giant star with a stellar classification of K0 III,^[4] or possibly a bright giant with a crossover class of G8/K1 II.^[3] The measured angular diameter of this star, after correction for limb darkening, is 2.48±0.03 mas.^[10] At the estimated distance of this star, this yields a physical size of about 38.6 times the radius of the Sun.^[6] It has an estimated 3.33 times the mass of the Sun and radiates 708 times the solar luminosity from its outer atmosphere at an effective temperature of 4,620 K.^[4]