18 Aurigae
Star in the constellation Auriga
From Wikipedia, the free encyclopedia
18 Aurigae is a star located 235[2] light years away from the Sun in the northern constellation of Auriga.[9] The brightness of this object is near the limit of visibility to the naked eye under good viewing conditions, appearing as a dim, white-hued star with an apparent visual magnitude of 6.49.[3] The star is moving away from the Sun with a heliocentric radial velocity of 6.5 km/s.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga[1] |
| Right ascension | 05h 19m 23.75369s[2] |
| Declination | +33° 59â² 07.3952â³[2] |
| Apparent magnitude (V) | 6.489[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | A7 V[4] |
| Apparent magnitude (G) | 6.45[2] |
| UâB color index | +0.09[5] |
| BâV color index | +0.256±0.007[1] |
| Astrometry | |
| Radial velocity (Rv) | 6.55±0.55[2] km/s |
| Proper motion (μ) | RA: +28.281±0.062[2] mas/yr Dec.: â12.715±0.044[2] mas/yr |
| Parallax (Ï) | 13.8604±0.0527 mas[2] |
| Distance | 235.3 ± 0.9 ly (72.1 ± 0.3 pc) |
| Absolute magnitude (MV) | 2.31[1] |
| Details | |
| Mass | 1.69±0.03[6] Mâ |
| Radius | 1.92+0.12 â0.03[7] Râ |
| Luminosity | 10.091±0.063[7] Lâ |
| Surface gravity (log g) | 4.26±0.14 cgs |
| Temperature | 7,432+231 â67[7] K |
| Rotational velocity (v sin i) | 124[6] km/s |
| Age | 950[8] Myr |
| Other designations | |
| 18 Aur, BD+33°1010, GC 6504, HD 34499, HIP 24832, HR 1734, SAO 57893, ADS 3893, WDS J05194+3359, Gaia DR3 182009826266321792[9] | |
| Database references | |
| SIMBAD | data |
This is an ordinary A-type main-sequence star with a stellar classification of A7 V,[4] which indicates it is generating energy by hydrogen fusion at its core. The object is 950[8] million years old with a high rate of spin, showing a projected rotational velocity of 124 km/s.[6] It has 1.7[6] times the mass of the Sun and 1.9[7] times the Sun's radius. The star is radiating 10[7] times the luminosity of the Sun from its photosphere at an effective temperature of 7,432 K.[7]
18 Aurigae has a magnitude 12.50 companion star at an angular separation of 3.90Ⳡalong a position angle of 167°, as of 2006.[10]