Epsilon Ceti
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 02h 39m 33.82853s[1] |
| Declination | −11° 52′ 19.7132″[1] |
| Apparent magnitude (V) | +4.84[2] |
| Characteristics | |
| Spectral type | F2V + F7/G4V[3] |
| U−B color index | −0.02[2] |
| B−V color index | +0.45[2] |
| Astrometry | |
| Proper motion (μ) | RA: +161.62[1] mas/yr Dec.: −230.53[1] mas/yr |
| Parallax (π) | 35.1 ± 1.0[1] mas |
| Distance | 93 ± 3 ly (28.5 ± 0.8 pc) |
| Orbit[3] | |
| Period (P) | 2.6512±0.0005 yr |
| Semi-major axis (a) | 0.1063±0.0005″ |
| Eccentricity (e) | 0.230±0.001 |
| Inclination (i) | 24.2±0.2° |
| Longitude of the node (Ω) | 90.2±0.2° |
| Periastron epoch (T) | 2012.3109±0.0005 |
| Argument of periastron (ω) (secondary) | 40.8±0.2° |
| Details | |
| ε Cet A | |
| Mass | 1.37±0.09[3] M☉ |
| Surface gravity (log g) | 4.21±0.14[4] cgs |
| Temperature | 6,537±222[4] K |
| Age | 1.8[4] Gyr |
| ε Cet B | |
| Mass | 1.03±0.08[3] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Epsilon Ceti (ε Ceti) is the Bayer designation for a binary star system located in the equatorial constellation of Cetus. It is faintly visible to the naked eye with an apparent visual magnitude of +4.84.[2] Based upon an annual parallax shift of 14.58 mas,[1] it is located around 98 light years away from the Sun.
This is a line-width spectroscopic binary star system. It has an orbital period of 2.65 years and an eccentricity of 0.23. The semimajor axis is 0.11 AU, or 11% of the distance between the Sun and the Earth, and the orbital plane is inclined at an angle of 24.2°.The primary member, component A, is an F-type main sequence star with a stellar classification of F2 V. The spectrum of the secondary, component B, can not be readily separated from that of the primary, so its type can only be estimated as a main sequence star lying in the range between F7 V and G4 V.[3] The system is estimated to be 1.8 billion years old,[4] with the primary having 1.4 times the mass of the Sun and the secondary being about equal to the Sun's mass.[3]
References
- 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752
, doi:10.1051/0004-6361:20078357. - 1 2 3 4 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M.
- 1 2 3 4 5 6 Docobo, J. A.; Andrade, M. (2013), "Dynamical and physical properties of 22 binaries discovered by W. S. Finsen", Monthly Notices of the Royal Astronomical Society, 428 (1): 321–339, Bibcode:2013MNRAS.428..321D, doi:10.1093/mnras/sts045.
- 1 2 3 4 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, Bibcode:2015ApJ...804..146D, arXiv:1501.03154 , doi:10.1088/0004-637X/804/2/146.
- ↑ "eps Cet -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-02-04.