51 Aurigae
K-type giant star in the constellation Auriga
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51 Aurigae is a single[8] star in the northern constellation of Auriga. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of about 5.70.[2] Based on parallax, it is located some 464 light-years (142 parsecs) away from the Sun.[1] It is receding from the Earth with a heliocentric radial velocity of 32 km/s.[4]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Auriga |
| Right ascension | 06h 38m 39.53667s[1] |
| Declination | +39° 23′ 27.0659″[1] |
| Apparent magnitude (V) | 5.696[2] |
| Characteristics | |
| Spectral type | K5III[2] |
| U−B color index | +1.56[3] |
| B−V color index | +1.34[3] |
| Astrometry | |
| Radial velocity (Rv) | 31.98±0.15[4] km/s |
| Proper motion (μ) | RA: −22.753[1] mas/yr Dec.: −108.896[1] mas/yr |
| Parallax (π) | 7.0332±0.1300 mas[1] |
| Distance | 464 ± 9 ly (142 ± 3 pc) |
| Absolute magnitude (MV) | 0.76[5] |
| Details | |
| Mass | 1.58±0.53[6] M☉ |
| Radius | 24.5±0.7[1] R☉ |
| Luminosity | 178.0±3.9[1] L☉ |
| Surface gravity (log g) | 1.84±0.11[6] cgs |
| Temperature | 4,277±92[6] K |
| Metallicity [Fe/H] | 0.01±0.05[6] dex |
| Age | 2.2[7] Gyr |
| Other designations | |
| 51 Aur, BD+39°1690, FK5 250, HD 47070, HIP 31771, HR 2419, SAO 59316 | |
| Database references | |
| SIMBAD | data |
At 2.2 billion years old,[7] 51 Aurigae has evolved off from the main sequence and is now a K-type giant star.[2] It is 1.58 times as massive as the Sun,[6] 24.5 times as wide, and 178 times as luminous.[1] It emits radiation from its photosphere with an effective temperature of about 4,277 K.[6]