Zeta Ceti
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 01h 51m 27.631s |
| Declination | −10° 20′ 06.112″ |
| 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: +39.752 mas/yr Dec.: −40.956 mas/yr |
| Parallax (π) | 12.8770±0.2100 mas |
| Distance | 253 ± 4 ly (78 ± 1 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 is a binary star system in the equatorial constellation of Cetus. Its name is a Bayer designation that is Latinized from ζ Ceti, and abbreviated Zeta Cet or ζ Cet. The system has a combined apparent visual magnitude of 3.74, which is bright enough to be seen with the naked eye as a point of light. Based upon parallax measurements, it is approximately 253 light-years (78 pc) distant from the Earth. The system is drifting further from the Sun with a line of sight velocity component of +11 km/s.
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.