Zeta Ceti
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 01h 51m 27.63482s |
| Declination | −10° 20′ 06.1289″ |
| Apparent magnitude (V) | 3.742 |
| Characteristics | |
| Spectral type | K0 III Ba0.1 |
| U−B color index | +1.076 |
| B−V color index | +1.131 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | +10.86±0.64 km/s |
| Proper motion (μ) | RA: +40.80 mas/yr Dec.: −37.25 mas/yr |
| Parallax (π) | 13.88±0.57 mas |
| Distance | 235 ± 10 ly (72 ± 3 pc) |
| Absolute magnitude (MV) | −0.54 |
| Orbit | |
| Period (P) | 1,652 d |
| Eccentricity (e) | 0.59 |
| Longitude of the node (Ω) | 85° |
| Periastron epoch (T) | 2414377 JD |
| Semi-amplitude (K1) (primary) | 3.3 km/s |
| Details | |
| ζ Cet A | |
| Mass | 2.34 M☉ |
| Radius | 25 R☉ |
| Luminosity | 240 L☉ |
| Surface gravity (log g) | 2.4 cgs |
| Temperature | 4,581±14 K |
| Metallicity [Fe/H] | −0.13 dex |
| Rotational velocity (v sin i) | 3.2 km/s |
| Age | 1.24 Gyr |
| Other designations | |
| Baten Kaitos, ζ Cet, 55 Cet, BD−11°359, FK5 62, HD 11353, HIP 8645, HR 539, SAO 148059, WDS J01515-1020A. | |
| Database references | |
| SIMBAD | data |
Zeta Ceti (ζ Ceti, abbreviated Zeta Cet, ζ Cet) is a binary star in the equatorial constellation of Cetus. It has a combined apparent visual magnitude of 3.74, which is bright enough to be seen with the naked eye. Based upon parallax measurements taken during the Hipparcos mission, it is approximately 235 light-years from the Sun.
Zeta Ceti is the primary or 'A' component of a double star system designated WDS J01515-1020 (the secondary or 'B' component is HD 11366). Zeta Ceti's two components are therefore designated WDS J01515-1020 Aa and Ab. Aa is officially named Baten Kaitos /ˈbeɪtən ˈkeɪtɒs/, the traditional name of the entire system.