Cetus () is a

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 ...

, sometimes called 'the whale' in English. The Cetus was a sea monster in Greek mythology which both

Perseus In Greek mythology, Perseus (Help:IPA/English, /ˈpɜːrsiəs, -sjuːs/; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus ...

and Heracles needed to slay. Cetus is in the region of the sky that contains other water-related constellations: Aquarius,

Pisces Pisces may refer to: * Pisces, an obsolete (because of land vertebrates) taxonomic superclass including all fish *Pisces (astrology), an astrological sign *Pisces (constellation), a constellation **Pisces Overdensity, an overdensity of stars in t ...

and Eridanus.

Features

Ecliptic

Cetus is not among the 12 true zodiac constellations in the J2000 epoch, nor classical 12-part zodiac. The ecliptic passes less than 0.25° from one of its corners. Thus the moon and planets will enter Cetus (occulting any stars as a foreground object) in 50% of their successive orbits briefly and the southern part of the sun appears in Cetus for about one day each year. Many asteroids in belts have longer phases occulting the north-western part of Cetus, those with a slightly greater inclination to the ecliptic than the moon and planets. As seen from Mars, the ecliptic (apparent plane of the sun and also the average plane of the planets which is almost the same) passes into it.

Stars

Mira ("wonderful", named by Bayer:

Omicron Ceti Mira (), designation Omicron Ceti (ο Ceti, abbreviated Omicron Cet, ο Cet), is a red-giant star estimated to be 200–400 light-years from the Sun in the constellation Cetus. ο Ceti is a Binary star, binary stellar system, consistin ...

, a star of the neck of the asterism) was the first variable star to be discovered and the prototype of its class, Mira variables. Over a period of 332 days, it reaches a maximum apparent magnitude of 3 - visible to the naked eye - and dips to a minimum magnitude of 10, invisible to the unaided eye. Its seeming appearance and disappearance gave it its name. Mira pulsates with a minimum size of 400 solar diameters and a maximum size of 500 solar diameters. 420 light-years from Earth, it was discovered by David Fabricius in 1596.

α Ceti Alpha Ceti (α Ceti, abbreviated Alpha Cet, α Cet), officially named Menkar , is the second-brightest star in the constellation of Cetus. It is a cool luminous red giant about 250 light years away. Nomenclature ''Alpha Ceti'' is th ...

, traditionally called Menkar ("the nose"), is a red-hued giant star of magnitude 2.5, 220 light-years from Earth. It is a wide

double star In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a bi ...

; the secondary is

93 Ceti 93 may refer to: * 93 (number) * one of the years 93 BC, AD 93, 1993, 2093, etc. * 93 Seine-Saint-Denis, French department, Paris, Île-de-France * Atomic number 93: neptunium * ''Ninety-Three'', English title of ''Quatrevingt-treize'' (same meanin ...

, a blue-white hued star of magnitude 5.6, 440 light-years away. β Ceti, also called Deneb Kaitos and Diphda is the brightest star in Cetus. It is an orange-hued giant star of magnitude 2.0, 96 light-years from Earth. The traditional name "Deneb Kaitos" means "the whale's tail".

γ Ceti Gamma Ceti (γ Ceti, abbreviated Gamma Cet, γ Cet) is a triple star system in the equatorial constellation of Cetus. It has a combined apparent visual magnitude of 3.47. Based upon parallax measurements, this star is located at a dista ...

, Kaffaljidhma ("head of the whale") is a very close double star. The primary is a yellow-hued star of magnitude 3.5, 82 light-years from Earth, and the secondary is a blue-hued star of magnitude 6.6. Tau Ceti is noted for being a near

Sun-like star Solar-type star, solar analogs (also analogues), and solar twins are stars that are particularly similar to the Sun. The stellar classification is a hierarchy with solar twin being most like the Sun followed by solar analog and then solar-typ ...

at a distance of 11.9 light-years. It is a yellow-hued main-sequence star of magnitude 3.5.

AA Ceti AA, Aa, Double A, or Double-A may refer to: Arts, entertainment and media * ''America's Army'', a 2002 computer game published by the U.S. Army * ''Ancient Anguish'', a computer game in existence since 1992 * Aa!, a J-Pop musical group * Doubl ...

is a triple star system; the brightest member has a magnitude of 6.2. The primary and secondary are separated by 8.4 arcseconds at an angle of 304 degrees. The tertiary is not visible in telescopes. AA Ceti is an eclipsing variable star; the tertiary star passes in front of the primary and causes the system's apparent magnitude to decrease by 0.5 magnitudes. UV Ceti is an unusual binary variable star. 8.7 light-years from Earth, the system consists of two

red dwarfs ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

. Both of magnitude 13. One of the stars is a flare star, which are prone to sudden, random outbursts that last several minutes; these increase the pair's apparent brightness significantly - as high as magnitude 7.

Deep-sky objects

Cetus lies far from the galactic plane, so that many distant

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

are visible, unobscured by dust from the Milky Way. Of these, the brightest is

Messier 77 Messier 77 or M77, also known as NGC 1068 and the Squid Galaxy, is a barred spiral galaxy about 47 million light-years away in the constellation Cetus. Messier 77 was discovered by Pierre Méchain in 1780, who originally described it as a nebul ...

(NGC 1068), a 9th magnitude

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Delta Ceti. It appears face-on and has a clearly visible nucleus of magnitude 10. About 50 million light-years from Earth, M77 is also a

Seyfert galaxy Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra ...

and thus a bright object in the radio spectrum. Recently, the galactic cluster JKCS 041 was confirmed to be the most distant cluster of galaxies yet discovered. The massive cD galaxy

Holmberg 15A Holmberg 15A (abbreviated to Holm 15A) is a supergiant elliptical galaxy and the central dominant galaxy of the Abell 85 galaxy cluster in the constellation Cetus, about 700 million light-years from Earth. It was discovered by Erik Holmber ...

is also found in Cetus. As is spiral galaxy NGC 1042 and ultra-diffuse galaxy NGC 1052-DF2. IC 1613 (

Caldwell Caldwell may refer to: People * Caldwell (surname) * Caldwell (given name) * Caldwell First Nation, a federally recognized Indian band in southern Ontario, Canada Places Great Britain * Caldwell, Derbyshire, a hamlet * Caldwell, East ...

51) is an irregular dwarf galaxy near the star 26 Ceti and is a member of the Local Group. NGC 246 (Caldwell 56), also called the Cetus Ring, is a planetary nebula with a magnitude of 8.0, 1600 light-years from Earth. Among some amateur astronomers, NGC 246 has garnered the nickname "Pac-Man Nebula" because of the arrangement of its central stars and the surrounding star field. The Wolf–Lundmark–Melotte (WLM) is a barred irregular galaxy discovered in 1909 by Max Wolf, located on the outer edges of the Local Group. The discovery of the nature of the galaxy was accredited to Knut Lundmark and Philibert Jacques Melotte in 1926. It is in the constellation Cetus.

History and mythology

Cetus may have originally been associated with a whale, which would have had mythic status amongst Mesopotamian cultures. It is often now called the Whale, though it is most strongly associated with Cetus the sea-monster, who was slain by

as he saved the princess Andromeda from Poseidon's wrath. It is in the middle of "The Sea" recognised by mythologists, a set of water-associated constellations, its other members being Eridanus,

, Piscis Austrinus and Aquarius. Cetus has been depicted in many ways throughout its history. In the 17th century, Cetus was depicted as a "dragon fish" by

Johann Bayer Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain, Lower Bavaria, in 1572. At twenty, in 1592 he began his study of philosophy and law at the University of Ingolstadt, a ...

. Both Willem Blaeu and

Andreas Cellarius Andreas Cellarius (–1665) was a Dutch–German cartographer and cosmographer best known for his 1660 '' Harmonia Macrocosmica'', a major star atlas. Life He was born in Neuhausen, and was educated in Heidelberg. The Protestant Cellariu ...

depicted Cetus as a whale-like creature in the same century. However, Cetus has also been variously depicted with animal heads attached to a piscine body.

In global astronomy

In Chinese astronomy, the stars of Cetus are found among two areas: the Black Tortoise of the North (北方玄武, ''Běi Fāng Xuán Wǔ'') and the White Tiger of the West (西方白虎, ''Xī Fāng Bái Hǔ''). The

Tukano The Tucano people (sometimes spelt Tukano) are a group of Indigenous South Americans in the northwestern Amazon, along the Vaupés River and the surrounding area. They are mostly in Colombia, but some are in Brazil. They are us ...

and

Kobeua people The Cubeo are an ethnic group of the Vaupés Department (Colombia). Cubeo is a generic name that is used in local Spanish and appears in the literature in reference to a social and linguistic group. Although the term does not have any meaning in ...

of the Amazon used the stars of Cetus to create a

jaguar The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...

, representing the god of hurricanes and other violent storms. Lambda, Mu, Xi, Nu, Gamma, and Alpha Ceti represented its head; Omicron, Zeta, and Chi Ceti represented its body; Eta Eri, Tau Cet, and Upsilon Cet marked its legs and feet; and Theta, Eta, and Beta Ceti delineated its tail. In Hawaii, the constellation was called ''Na Kuhi'', and Mira (Omicron Ceti) may have been called ''Kane''.

Namesakes

USS Cetus (AK-77) USS ''Cetus'' (AK-77) was a in the service of the US Navy in World War II. Named after the equatorial constellation Cetus, it was the only ship of the Navy to bear this name. Construction ''Cetus'' was laid down 21 November 1942 as liberty ...

was a United States Navy Crater class cargo ship named after the constellation. "Cetus" is the title of a ragtime piano composition by Tom Brier on the album ''Constellations'' and a 1967 electronic composition by Olly Wilson.

Gallery

File:Clash_of_the_Titans.tif, The interacting galaxy pair IC 1623, which lies around 275 million light-years away in the constellation Cetus (The Whale).

References

Bibliography

* * * * Ian Ridpath and Wil Tirion (2007). ''Stars and Planets Guide'', Collins, London. . Princeton University Press, Princeton. *

External links

*
The Deep Photographic Guide to the Constellations: Cetus

Warburg Institute Iconographic Database (over 170 medieval and early modern images of Cetus)
{{DEFAULTSORT:Cetus Constellations Equatorial constellations Constellations listed by Ptolemy Fictional cetaceans Legendary mammals