Tau Aurigae

Tau Aurigae, Latinized from τ Aurigae, is a star in the northern constellation Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.505,^[2] and is approximately 207 light-years (63 parsecs) distant from Earth.

τ Aurigae

Location of τ Aurigae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	05h 49m 10.43826s[1]
Declination	+39° 10′ 51.8627″[1]
Apparent magnitude (V)	4.505[2]
Characteristics
Spectral type	G8 III[3]
U−B color index	+0.692[2]
B−V color index	+0.956[2]
R−I color index	0.49
Astrometry
Radial velocity (Rv)	–19.32 ± 0.19[4] km/s
Proper motion (μ)	RA: –28.30[1] mas/yr Dec.: –24.97[1] mas/yr
Parallax (π)	15.5940 ± 0.2061 mas[5]
Distance	209 ± 3 ly (64.1 ± 0.8 pc)
Absolute magnitude (MV)	0.50[6]
Details
Mass	2.55[7] M☉
Radius	11[4] R☉
Luminosity	63[4] L☉
Surface gravity (log g)	2.7[4] cgs
Temperature	4,887[4] K
Metallicity [Fe/H]	–0.27[4] dex
Rotational velocity (v sin i)	3.8[4] km/s
Age	660 - 890[7] Myr
Other designations
τ Aur, 29 Aurigae, BD+39 1418, HD 38656, HIP 27483, HR 1995, SAO 58465.[8]
Database references
SIMBAD	data

Tau Aurigae is an evolved giant star with a stellar classification of G8 III.^[3] It has expanded to 11 times the radius of the Sun and shines with 63 times the Sun's luminosity. This energy is radiated into outer space from the outer atmosphere at an effective temperature of 4,887.^[4] This heat gives it the yellow-hued glow of a G-type star.^[9]