Zeta Aurigae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 02m 28.683s |
| Declination | +41° 04′ 33.00″ |
| Apparent magnitude (V) | 3.751 (3.70–3.97) |
| Characteristics | |
| Spectral type | K5II (or K5Ib) + B7 V |
| U−B color index | +0.374 |
| B−V color index | +1.293 |
| R−I color index | 0.87 |
| Variable type | Algol |
| Astrometry | |
| Radial velocity (Rv) | +12.11 km/s |
| Proper motion (μ) | RA: +12.093 mas/yr Dec.: −19.324 mas/yr |
| Parallax (π) | 3.791±0.05 mas |
| Distance | 860 ± 10 ly (264 ± 3 pc) |
| Absolute magnitude (MV) | −3.21 |
| Orbit | |
| Period (P) | 972.162 d (2.66 yr) |
| Semi-major axis (a) | 905 R☉ |
| Eccentricity (e) | 0.3973±0.0007 |
| Inclination (i) | 87.0° |
| Periastron epoch (T) | RJD 53039.9 ± 0.10 |
| Argument of periastron (ω) (secondary) | 328.9°±0.13° |
| Semi-amplitude (K1) (primary) | 23.17±0.02 km/s |
| Details | |
| ζ Aur A | |
| Mass | 5.8±0.2 M☉ |
| Radius | 148±3 R☉ |
| Luminosity | 4,786 L☉ |
| Surface gravity (log g) | 1.33 cgs |
| Temperature | 3,960±100 K |
| Metallicity [Fe/H] | −0.26 dex |
| Rotational velocity (v sin i) | 5.7±1 km/s |
| ζ Aur B | |
| Mass | 4.8±0.2 M☉ |
| Radius | 4.5±0.5 R☉ |
| Temperature | 15,200±200 K |
| Other designations | |
| Saclateni, ζ Aur, Zeta Aur, 8 Aurigae, BD+40°1142, FK5 1137, GC 6137, HD 32068, HIP 23453, HR 1612, SAO 39966, PPM 47641, WDS 05025+4105 | |
| Database references | |
| SIMBAD | data |
Zeta Aurigae is an eclipsing binary star system in the northern constellation of Auriga. Its name is a Bayer designation that is Latinized from ζ Aurigae, and abbreviated Zeta Aur or ζ Aur. Based upon parallax measurements, this system is approximately 860 light-years (260 parsecs) distant from the Sun. It has a combined apparent visual magnitude of 3.75, which is bright enough to be seen with the naked eye. The system is drifting further away from the Sun with a radial velocity of +12 km/s.
The two components are designated Zeta Aurigae A and B. The bright giant or supergiant component A has the official name Saclateni, pronounced /sækləˈtiːni/, which is an old misspelling of "Sadatoni". Its hotter companion is a B-type dwarf. The pair orbit each other with a period of 2.66 yr.