Upsilon Aurigae

υ Aurigae

Template:Location mark Location of υ Aurigae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	4.74
Characteristics
Evolutionary stage	Asymptotic giant branch
Spectral type	M0 III
U−B Template:Engvar	+1.93
B−V Template:Engvar	+1.62
R−I Template:Engvar	1.07
Variable type	Suspected
Astrometry
Radial velocity (Rv)	+37.62±0.34 km/s
Proper motion (μ)	RA: +36.426 mas/yr Dec.: −45.606 mas/yr
Parallax (π)	5.7358±0.2055 mas
Distance	Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)	−1.28
Details
Mass	Template:Val Template:Solar mass
Radius	Template:Val Template:Solar radius
Luminosity	Template:Val Template:Solar luminosity
Surface gravity (log g)	Template:Val cgs
Temperature	Template:Val K
Age	Template:Val Gyr
Metallicity [Fe/H]	{{{metal_fe2}}} dex
Other designations
Template:Odlist
Database references
SIMBAD	data

Upsilon Aurigae is a single star in the northern constellation of Auriga. Its name is a Bayer designation that is Latinised from υ Aurigae, and abbreviated Upsilon Aur or υ Aur. This star has an apparent visual magnitude of 4.74, which means it is bright enough to be seen with the naked eye. Based upon parallax measurements, this star is approximately Template:Convert distant from the Earth. It is drifting further away with a radial velocity of +37 km/s.

This is an evolved red giant star with a stellar classification of M0 III. It is a suspected variable star and is currently on the asymptotic giant branch, which means it is generating energy through the fusion of helium along a shell surrounding a small, inert core of carbon and oxygen. The star is two billion years old with 1.64 times the mass of the Sun and has expanded to 61 times the Sun's radius. It is radiating 1,165 times the Sun's luminosity from its photosphere at an effective temperature of Template:Val.

External links

• HR 2011
• Image Upsilon Aurigae