HD 79940

This article is about k Velorum and is not to be confused with κ (Kappa) Velorum.

HD 79940 is a single^[10] star in the southern constellation of Vela. It has the Bayer designation of k Velorum; HD 79940 is the identifier from the Henry Draper Catalogue. This star has a yellow-white hue and is faintly visible to the naked eye as a point light source with an apparent visual magnitude of 4.63.^[2] It is located at a distance of approximately 158 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +6 km/s.^[2]

HD 79940

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Vela
Right ascension	09h 15m 45.07943s[1]
Declination	−37° 24′ 47.3124″[1]
Apparent magnitude (V)	4.63[2]
Characteristics
Spectral type	F3/5V[3] or F5III[4][5]
B−V color index	0.473±0.002[2]
Astrometry
Radial velocity (Rv)	+5.8±2.8[2] km/s
Proper motion (μ)	RA: +14.128[1] mas/yr Dec.: −8.111[1] mas/yr
Parallax (π)	20.5985±0.1895 mas[1]
Distance	158 ± 1 ly (48.5 ± 0.4 pc)
Absolute magnitude (MV)	1.12[2]
Details
Mass	1.36[6] M☉
Radius	4.35+0.11 −0.19[1] R☉
Luminosity	28.427±0.305[1] L☉
Surface gravity (log g)	3.26±0.14[6] cgs
Temperature	6,388+143 −76[1] K
Metallicity [Fe/H]	0.20±0.15[2] dex
Rotational velocity (v sin i)	117.2±5.9[7] km/s
Age	2.76[6] Gyr
Other designations
k Vel, CD−36 5505, GJ 339.3, GJ 9293, HD 79940, HIP 45448, HR 3684, SAO 200163, WDS J09158-3725A,[8] k2 Vel[9]
Database references
SIMBAD	data

There has been some disagreement over the stellar classification of this star. In 1975, S. Maladora found a class of F5III, suggesting an evolved F-type star,^[4] matching an earlier (1957) classification by A. de Vaucouleurs.^[5] N. Houk assigned it a class of F3/5V in 1979, matching an F-type main-sequence star.^[3] It has a high rate of spin with a projected rotational velocity of 117.2±5.9 km/s.^[7] This may explain why it was incorrectly classified as a spectroscopic binary in 1972.^[10]

There is a faint magnitude 14.50 companion at an angular separation of 11.3″ along a position angle of 126° from the brighter star. This was discovered by T. J. J. See in 1897.^[11]