Crater is a small

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

in the

southern celestial hemisphere The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appear ...

. Its name is the

latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

ization of the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

'' krater'', a type of

cup A cup is an open-top used to hold hot or cold liquids for pouring or drinking; while mainly used for drinking, it also can be used to store solids for pouring (e.g., sugar, flour, grains, salt). Cups may be made of glass, metal, china, cl ...

used to water down

wine Wine is an alcoholic drink typically made from Fermentation in winemaking, fermented grapes. Yeast in winemaking, Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different ...

. One of the 48 constellations listed by the second-century astronomer

Ptolemy Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...

, it depicts a cup that has been associated with the god

Apollo Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...

and is perched on the back of Hydra the water snake. There is no

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

brighter than third magnitude in the constellation. Its two brightest stars, Delta Crateris of magnitude 3.56 and Alpha Crateris of magnitude 4.07, are ageing orange

giant star A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Press ...

s that are cooler and larger than the Sun. Beta Crateris is 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 ...

system composed of a white giant star and a

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...

. Seven star systems have been found to host

planets A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a youn ...

. A few notable

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 ...

, including Crater 2 and NGC 3981, and a famous

quasar A quasar is an extremely luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass rangi ...

lie within the borders of the constellation.

Mythology

In the

Babylonian star catalogues Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, ...

dating from at least 1100 BC, the stars of Crater were possibly incorporated with those of the crow Corvus in the Babylonian Raven (MUL.UGA.MUSHEN). British scientist John H. Rogers observed that the adjoining constellation Hydra signified Ningishzida, the god of the

underworld The underworld, also known as the netherworld or hell, is the supernatural world of the dead in various religious traditions and myths, located below the world of the living. Chthonic is the technical adjective for things of the underwo ...

in the Babylonian compendium MUL.APIN. He proposed that Corvus and Crater (along with the water snake Hydra) were death symbols and marked the gate to the underworld. Corvus and Crater also featured in the iconography of

Mithraism Mithraism, also known as the Mithraic mysteries or the Cult of Mithras, was a Roman mystery religion centered on the god Mithras. Although inspired by Iranian worship of the Zoroastrian divinity ('' yazata'') Mithra, the Roman Mithras is li ...

, which is thought to have been of middle-eastern origin before spreading into Ancient Greece and Rome. Crater is identified with a story from

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities o ...

in which a crow or raven serves

, and is sent to fetch water, but it delays its journey as it finds some figs and waits for them to ripen before eating them. Finally it retrieves the water in a cup, and takes back a water snake, blaming it for drinking the water. According to the myth, Apollo saw through the fraud, and angrily cast the crow, cup, and snake, into the sky. The three constellations were arranged in such a way that the crow was prevented from drinking from the cup, and hence seen as a warning against sinning against the gods. Phylarchus wrote of a different origin for Crater. He told how the city of Eleusa near

Troy Troy ( el, Τροία and Latin: Troia, Hittite: 𒋫𒊒𒄿𒊭 ''Truwiša'') or Ilion ( el, Ίλιον and Latin: Ilium, Hittite: 𒃾𒇻𒊭 ''Wiluša'') was an ancient city located at Hisarlik in present-day Turkey, south-west of Ç ...

was beset by plague. Its ruler Demiphon consulted an oracle which decreed that a maiden should be sacrificed each year. Demiphon declared that he would choose a maiden by lottery, but he did not include his own daughters. One nobleman, Mastusius, objected, forcing Demiphon to sacrify his daughter. Later, Mastusius killed Demiphon's daughters and tricked the ruler in drinking a cup containing a mixture of their blood and wine. Upon finding out the deed, the king ordered Mastusius and the cup to be thrown into the sea. Crater signifies the cup.

In other cultures

Chinese astronomy Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the tw ...

, the stars of Crater are located within the constellation of the Vermillion Bird of the South (南方朱雀, ''Nán Fāng Zhū Què''). They depict, along with some stars from Hydra, ''Yi'', the Red Bird's wings. ''Yi'' also denotes the 27th

lunar mansion Often called lunar mansion, a lunar station or lunar house is a segment of the ecliptic through which the Moon passes in its orbit around the Earth. The concept was used by several ancient cultures as part of their calendrical system. Stations ...

. Alternatively, ''Yi'' depicts a heroic bowman; his bow composed of other stars in Hydra. In the

Society Islands The Society Islands (french: Îles de la Société, officially ''Archipel de la Société;'' ty, Tōtaiete mā) are an archipelago located in the South Pacific Ocean. Politically, they are part of French Polynesia, an overseas country of the F ...

, Crater was recognized as a constellation called ''Moana-'ohu-noa-'ei-ha'a-moe-hara'' ("vortex-ocean-in-which-to-lose-crime").

Characteristics

Covering 282.4 square degrees and hence 0.685% of the sky, Crater ranks 53rd of the 88 constellations in area. It is bordered by Leo and

Virgo Virgo may refer to: *Virgo (astrology), the sixth astrological sign of the zodiac * Virgo (constellation), a constellation *Virgo Cluster, a cluster of galaxies in the constellation Virgo *Virgo Stellar Stream, remains of a dwarf galaxy * Virgo Su ...

to the north, Corvus to the east, Hydra to the south and west, and Sextans to the northwest. The three-letter abbreviation for the constellation, as adopted by the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

in 1922, is "Crt". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of six segments (''illustrated in infobox''). In the

equatorial coordinate system The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects. It may be implemented in spherical or rectangular coordinates, both defined by an origin at the centre of Earth, a fu ...

, the

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the ( hour circle of the) point in question above the earth. When pair ...

coordinates of these borders lie between and , while the

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of th ...

coordinates are between −6.66° and −25.20°. Its position in the

means that the whole constellation is visible to observers south of 65°N.

Features

Stars

The German cartographer

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, ...

used the Greek letters

alpha Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whi ...

through

lambda Lambda (}, ''lám(b)da'') is the 11th letter of the Greek alphabet, representing the voiced alveolar lateral approximant . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoenician Lamed . Lambda gave ri ...

to label the most prominent stars in the constellation. Bode added more, though only Psi Crateris remains in use.

John Flamsteed John Flamsteed (19 August 1646 – 31 December 1719) was an English astronomer and the first Astronomer Royal. His main achievements were the preparation of a 3,000-star catalogue, ''Catalogus Britannicus'', and a star atlas called '' Atlas C ...

gave 31 stars in Crater and the segment of Hydra immediately below Crater

Flamsteed designation A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the modern constellations visible from southern England. They are named for John Flamsteed who first used them while co ...

s, naming the resulting constellation Hydra et Crater. Most of these stars lie in Hydra. The three brightest stars— Delta,

Alpha Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whi ...

and Gamma Crateris—form a triangle located near the brighter star Nu Hydrae in Hydra. Within the constellation's borders, there are 33 stars brighter than or equal to

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

6.5. Delta Crateris is the brightest star in Crater at magnitude 3.6. Located 163 ± 4

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distance, astronomical distances and is equivalent to about 9.46 Orders of magnitude (numbers)#1012, trillion kilometers (), or 5.88 ...

s away, it is an orange

spectral type In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

K0III that is 1.0–1.4 times as massive as the Sun. An ageing star, it has cooled and expanded to times the Sun's radius. It is radiating as much power as the Sun from its outer envelope at an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of . Traditionally called Alkes "the cup", and marking the base of the cup is Alpha Crateris, an orange-hued star of magnitude 4.1, that is 141 ± 2 light-years from the Sun. With an estimated mass 1.75 ± 0.24 times that of the Sun, it has exhausted its core hydrogen and expanded to 13.2 ± 0.55 times the Sun's diameter, shining with 69 times its luminosity and an effective temperature of around 4600 K. With a magnitude of 4.5, Beta Crateris is a

system, consisting of a white-hued giant star of spectral type A1III and a

of spectral type DA1.4, 296 ± 8 light-years from the Sun. Much smaller than the primary, the white dwarf cannot be seen as a separate object, even by the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most vers ...

. Gamma Crateris is a

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 ...

, resolvable in small amateur telescopes. The primary is a white main sequence star of spectral type A7V, that is an estimated 1.81 times as massive as the Sun, while the secondary—of magnitude 9.6—has 75% the Sun's mass, and is likely an orange dwarf. The two stars take at least 1150 years to orbit each other. The system is 85.6 ± 0.8 light-years away from the Sun.

Epsilon Epsilon (, ; uppercase , lowercase or lunate ; el, έψιλον) is the fifth letter of the Greek alphabet, corresponding phonetically to a mid front unrounded vowel or . In the system of Greek numerals it also has the value five. It was d ...

and Zeta Crateris mark the Cup's rim. The largest naked eye star in the constellation, Epsilon Crateris is an

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variati ...

K-type giant star with a

stellar classification In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

of K5 III. It has about the same mass as the Sun, but has expanded to 44.7 times the Sun's radius. The star is radiating 391 times the solar luminosity. It is 366 ± 8 light-years distant from the Sun. Zeta Crateris is a binary star system. The primary, component A, is a magnitude 4.95 evolved giant star with a stellar classification of G8 III. It is a red clump star that is generating energy through the fusion of helium at its core. Zeta Crateris has expanded to 13 times the radius of the Sun, and shines with 157 times the luminosity of the Sun.Online data
( HIP number needed) The secondary, component B, is a magnitude 7.84 star. Zeta Crateris is a confirmed member of the Sirius supercluster and is a candidate member of the Ursa Major Moving Group, a collection of stars that share a similar motion through space and may have at one time been members of the same

open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, an ...

. The system is located 326 ± 9 light-years from the Sun. Variable stars are popular targets for amateur astronomers, their observations providing valuable contributions to understanding star behaviour. Located near Alkes is the red-hued R Crateris, a

semiregular variable star In astronomy, a semiregular variable star, a type of variable star, is a giant or supergiant of intermediate and late (cooler) spectral type showing considerable periodicity in its light changes, accompanied or sometimes interrupted by various irre ...

of type SRb and a

spectral classification In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting th ...

of M7. It ranges from magnitude 9.8 to 11.2 over an optical period of 160 days. It is 770 ± 40 light-years distant from the Sun. TT Crateris is a

cataclysmic variable In astronomy, cataclysmic variable stars (CVs) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state. They were initially called novae (), since ones with an outburst brightness visible to ...

; a binary system composed of a white dwarf around as massive as the Sun in close orbit with an orange dwarf of spectral type K5V. The two orbit each other every 6 hours 26 minutes. The white dwarf strips matter off its companion, forming an

accretion disk An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star. Friction, uneven irradiance, magnetohydrodynamic effects, and other ...

which periodically ignites and erupts. The star system has a magnitude of 15.9 when quiescent, brightening to 12.7 in outburst. SZ Crateris is a magnitude 8.5

BY Draconis BY Draconis is a multiple star system in the constellation Draco, consisting of at least three components. Components A and B are main sequence stars, and form a close binary star system with a short orbital period of only 5.98 days. T ...

type variable star. It is a nearby star system located about 42.9 ± 1.0 light-years from the Sun, and is a member of the Ursa Major Moving Group.

HD 98800 HD 98800, also catalogued as TV Crateris (TV Crt), is a quadruple star system in the constellation of Crater (the cup). Parallax measurements made by the Hipparcos spacecraft put it at a distance of about 150 light-years (45 parsecs) ...

, also known as TV Crateris, is a quadruple star system around 7–10 million years old, made up of two pairs of stars in close orbit. One pair has a debris disk that contains dust and gas orbiting them both. Spanning the distance between 3 and 5 astronomical units from the stars, it is thought to be a

protoplanetary disk A protoplanetary disk is a rotating circumstellar disc of dense gas and dust surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star. The protoplanetary disk may also be considered an accretion disk for the star itself, be ...

. DENIS-P J1058.7-1548 is a

brown dwarf Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...

less than 5.5% as massive as the Sun. With a surface temperature of between 1700 and 2000 K, it is cool enough for clouds to form. Variations in its brightness in visible and infrared spectra suggest it has some form of atmospheric cloud cover. HD 96167 is a star 1.31 ± 0.09 times as massive as the Sun, that has most likely exhausted its core hydrogen and begun expanding and cooling into a yellow subgiant with a diameter 1.86 ± 0.07 times that of the Sun, and 3.4 ± 0.2 times its luminosity. Analysis of its radial velocity revealed it has a planet with a minimum mass 68% that of Jupiter, which takes 498.9 ± 1.0 days to complete an orbit. With the orbital separation varying between 0.38 and 2.22 astronomical units, the orbit is highly

eccentric Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-center, in geometry * Eccentricity (graph theory) of a v ...

. The stellar system is 279 ± 1 light-years away from the Sun. HD 98649 is a yellow main sequence star, classified as a G4V, that has the same mass and diameter as the Sun, but has only 86% of its luminosity. In 2012, a long-period ( 4951 days) planet companion, at least 6.8 times as massive as Jupiter, was discovered by

radial velocity method Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in th ...

. Its orbit was calculated to be highly eccentric, swinging out to 10.6 astronomical units away from its star, and hence a candidate for direct imaging. BD-10°3166 is a metallic orange main sequence star of spectral type K3.0V, 268 ± 10 light-years distant from the Sun. It was found to have a

hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere t ...

-type planet that has a minimum mass of 48% of

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousand ...

's, and takes only 3.49 days to complete an orbit. WASP-34 is a sun-like star of spectral type G5V that has 1.01 ± 0.07 times the mass and 0.93 ± 0.12 times the diameter of the Sun. It has a planet 0.59 ± 0.01 times as massive as Jupiter that takes 4.317 days to complete an orbit. The system is 432 ± 3 light-years distant from the Sun.

Deep-sky objects

The Crater 2 dwarf is a satellite galaxy of the Milky Way, located approximately 380,000 light-years from the Sun. NGC 3511 is a

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''NGC 3513, a barred spiral galaxy. NGC 3981 is a spiral galaxy with two wide and perturbed spiral arms. It is a member of the NGC 4038 Group, which, along with

NGC 3672 NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * Nati ...

and NGC 3887, are part of a group of 45 galaxies known as the Crater Cloud within the

Virgo Supercluster The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least ...

. RX J1131 is a

located 6 billion light-years away from the Sun. The black hole in the center of the quasar was the first black hole whose spin has ever been directly measured.

GRB 011211 GRB 011211 was a gamma-ray burst (GRB) detected on December 11, 2001. A gamma-ray burst is a highly luminous flash associated with an explosion in a distant galaxy and producing gamma rays, the most energetic form of electromagnetic radiation ...

was a

gamma-ray burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten millise ...

(GRB) detected on December 11, 2001. The burst lasted 270 seconds, making it the longest burst that had ever been detected by X-ray astronomy satellite

BeppoSAX BeppoSAX was an Italian–Dutch satellite for X-ray astronomy which played a crucial role in resolving the origin of gamma-ray bursts (GRBs), the most energetic events known in the universe. It was the first X-ray mission capable of simultaneous ...

up to that point. GRB 030323 lasted 26 seconds, and was detected on 23 March 2003.

Meteor showers

The Eta Craterids are a faint meteor shower that takes place between 11 and 22 January, peaking around January 16 and 17.

Notes

References

External links

The Deep Photographic Guide to the Constellations: Crater

Warburg Institute Iconographic Database (medieval and early modern images of Crater)
{{DEFAULTSORT:Crater (Constellation) Constellations Southern constellations Constellations listed by Ptolemy