Epsilon Ceti, Latinized from ε Ceti, is the

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

for a

binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

system located in the

equatorial Equatorial may refer to something related to: *Earth's equator **the tropics, the Earth's equatorial region **tropical climate *the Celestial equator ** equatorial orbit **equatorial coordinate system ** equatorial mount, of telescopes * equatorial ...

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

of Cetus. It is faintly visible to the naked eye with an apparent visual magnitude of +4.84. Based upon an annual parallax shift of 14.58

mas Mas, Más or MAS may refer to: Film and TV * Más y Menos, fictional superhero characters, from the Teen Titans animated television series * Más (Breaking Bad), "Más" (''Breaking Bad''), a season three episode of ''Breaking Bad'' Songs * Más ( ...

, it is located around 98

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s away from the Sun. This is a line-width

spectroscopic binary A binary star is a system of two star, stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separa ...

star system. It has an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 2.65 years and an eccentricity of 0.23. The

semimajor axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longe ...

is , or 11% of the distance between the Sun and the Earth, and the orbital plane is

inclined Incline, inclined, inclining, or inclination may refer to: *Grade (slope), the tilt, steepness, or angle from horizontal of a topographic feature (hillside, meadow, etc.) or constructed element (road, railway, field, etc.) *Slope, the tilt, steepn ...

at an angle of 24.2°.The primary member, component A, is an F-type main-sequence star with a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

of F2 V. The

spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors i ...

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. The system is estimated to be 1.8 billion years old, with the primary having 1.4 times the

mass of the Sun The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

and the secondary being about equal to the Sun's mass.

Name

This star, along with π Cet, ρ Cet and σ Cet, was Al Sufi's Al Sadr al Ḳaiṭos, the Whale's Breast. According to the catalogue of stars in the ''Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars'', ''Al Sadr al Ḳaiṭos'' were the title for four stars: ρ Cet as ''Al Sadr al Ḳaiṭos I'', σ Cet as ''Al Sadr al Ḳaiṭos II'', this star (ε Cet) as ''Al Sadr al Ḳaiṭos III'' and π Cet as ''Al Sadr al Ḳaiṭos IV''. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

, (), meaning ''

Hay Hay is grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, goats, and sheep, or for smaller domesticated ...

'', refers to an asterism consisting of ε Ceti, ρ Ceti, 77 Ceti, 67 Ceti, 71 Ceti and HD 14691. 夢之大地 @ 國立成功大學 WebBBS DreamLand @ National Cheng Kung University WebBBS System
/ref> Consequently, the Chinese name for ε Ceti itself is (, en, the Sixth Star of Celestial Meadows).
AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 12 日

References

{{DEFAULTSORT:Epsilon Ceti Cetus, Epsilon Spectroscopic binaries Cetus Cetus, Epsilon BD-12 501 Ceti, 83 016620 012390 0781