Nu Aurigae

ν Aurigae
Location of ν Aurigae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension 05h 51m 29.36946s
Declination +39° 08 54.6861
Apparent magnitude (V) 3.957
Characteristics
Evolutionary stage red clump
Spectral type G9.5 III Fe1 Ba0.2 + wd
U−B color index +1.084
B−V color index +1.138
R−I color index 0.56
Astrometry
Radial velocity (Rv)+9.92±0.14 km/s
Proper motion (μ) RA: +7.958 mas/yr
Dec.: +0.713 mas/yr
Parallax (π)16.1414±0.4427 mas
Distance202 ± 6 ly
(62 ± 2 pc)
Absolute magnitude (MV)−0.27
Details
Mass2.12 M
Radius17.85+0.51
−0.53
 R
Luminosity126±8 L
Surface gravity (log g)2.4 cgs
Temperature4,576±50 K
Metallicity [Fe/H]−0.14 dex
Rotational velocity (v sin i)5.0 km/s
Age1.11 Gyr
Other designations
ν Aur, 32 Aurigae, BD+39 1429, FK5 221, GC 7334, HD 39003, HIP 27673, HR 2012, SAO 58502, PPM 70925, ADS 4440, WDS J05515+3909A
Database references
SIMBADdata

Nu Aurigae is a star in the northern constellation of Auriga. Its name is a Bayer designation that is Latinised from ν Aurigae, and abbreviated Nu Aur or ν Aur. This star is visible to the naked eye with an apparent visual magnitude of 3.96. Based on parallax measurements, it is approximately 202 light-years (62 parsecs) distant from the Earth. The star is drifting further away from the Sun with a radial velocity of +10 km/s.

This is an evolved giant star with a stellar classification of G9.5 III. At 1.1 billion years of age, it is a red clump star that is generating energy through the fusion of helium at its core. Its outer envelope has expanded to 18 times the radius of the Sun and cooled to 4,576 K, giving it the characteristic yellow-hued glow of a G-type star. It shines with 126 times the luminosity of the Sun and has 2.12 times the Sun's mass.

This is an astrometric binary with a suspected white dwarf companion. Radial velocity variations suggest an orbital period of 20.18 ± 0.85 yr (7,370 ± 310 d) with a large eccentricity of 0.71. A 10th-magnitude star 54.6 arcseconds away is an optical companion.