Nu Aurigae
Variable star in the constellation Auriga
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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.[3] Based on parallax measurements, it is approximately 202 light-years (62 parsecs) distant from the Earth.[2] The star is drifting further away from the Sun with a radial velocity of +10 km/s.[6]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga[1] |
| Right ascension | 05h 51m 29.36946s[2] |
| Declination | +39° 08′ 54.6861″[2] |
| Apparent magnitude (V) | 3.957[3] |
| Characteristics | |
| Evolutionary stage | red clump[4] |
| Spectral type | G9.5 III Fe1 Ba0.2 + wd[5] |
| U−B color index | +1.084[3] |
| B−V color index | +1.138[3] |
| R−I color index | 0.56 |
| Astrometry | |
| Radial velocity (Rv) | +9.92±0.14[6] km/s |
| Proper motion (μ) | RA: +7.958 mas/yr[2] Dec.: +0.713 mas/yr[2] |
| Parallax (π) | 16.1414±0.4427 mas[2] |
| Distance | 202 ± 6 ly (62 ± 2 pc) |
| Absolute magnitude (MV) | −0.27[1] |
| Details | |
| Mass | 2.12[7] M☉ |
| Radius | 17.85+0.51 −0.53[8] R☉ |
| Luminosity | 126±8[8] L☉ |
| Surface gravity (log g) | 2.4[6] cgs |
| Temperature | 4,576±50[8] K |
| Metallicity [Fe/H] | −0.14[6] dex |
| Rotational velocity (v sin i) | 5.0[6] km/s |
| Age | 1.11[7] 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[9] | |
| Database references | |
| SIMBAD | data |
This is an evolved giant star with a stellar classification of G9.5 III.[10] At 1.1 billion years of age,[7] it is a red clump star that is generating energy through the fusion of helium at its core.[4] Its outer envelope has expanded to 18 times the radius of the Sun and cooled to 4,576 K,[8] giving it the characteristic yellow-hued glow of a G-type star.[11] It shines with 126 times the luminosity of the Sun[8] and has 2.12 times the Sun's mass.[7]
This is an astrometric binary with a suspected white dwarf companion.[5] Radial velocity variations suggest an orbital period of 20.18 ± 0.85 yr (7,370 ± 310 d) with a large eccentricity of 0.71.[12] A 10th-magnitude star 54.6 arcseconds away is an optical companion.