Cancer is one of the twelve
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 ...
s of the
zodiac
The zodiac is a belt-shaped region of the sky that extends approximately 8° north or south (as measured in celestial latitude) of the ecliptic, the Sun path, apparent path of the Sun across the celestial sphere over the course of the year. ...
and is located in the
Northern celestial hemisphere. Its old astronomical symbol is (♋︎). Its name is
Latin
Latin (, or , ) is a classical language belonging to the 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 the power of the ...
for
crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
and it is commonly represented as one. Cancer is a medium-size constellation with an area of 506
square degree
__NOTOC__
A square degree (deg2) is a non- SI unit measure of solid angle. Other denotations include ''sq. deg.'' and (°)2. Just as degrees are used to measure parts of a circle, square degrees are used to measure parts of a sphere. Analogous to ...
s and its stars are rather faint, its brightest star
Beta Cancri having an
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 li ...
of 3.5. It contains two stars with known
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 young ...
, including
55 Cancri, which has five: one
super-earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively.
The term "super-Earth" refers only to ...
and four
gas giant
A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" ...
s, one of which is in the
habitable zone
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Kas ...
and as such has expected temperatures similar to Earth. At the (angular) heart of this sector of our celestial sphere is
Praesepe
The Beehive Cluster (also known as Praesepe (Latin for "manger" or "crib"), M44, NGC 2632, or Cr 189), is an open cluster in the constellation Cancer. One of the nearest open clusters to Earth, it contains a larger population of stars than other ...
(Messier 44), one of the closest
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, and ...
s to Earth and a popular target for amateur astronomers.
Characteristics
Cancer is a medium-sized constellation that is bordered by
Gemini
Gemini may refer to:
Space
* Gemini (constellation), one of the constellations of the zodiac
** Gemini in Chinese astronomy
* Project Gemini, the second U.S. crewed spaceflight program
* Gemini Observatory, consisting of telescopes in the Norther ...
to the west,
Lynx
A lynx is a type of wild cat.
Lynx may also refer to:
Astronomy
* Lynx (constellation)
* Lynx (Chinese astronomy)
* Lynx X-ray Observatory, a NASA-funded mission concept for a next-generation X-ray space observatory
Places Canada
* Lynx, Ontar ...
to the north,
Leo Minor
Leo Minor is a small and faint constellation in the northern celestial hemisphere. Its name is Latin for "the smaller lion", in contrast to Leo, the larger lion. It lies between the larger and more recognizable Ursa Major to the north and Le ...
to the northeast,
Leo to the east,
Hydra to the south, and
Canis Minor to the southwest. 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 "Cnc".
The official constellation boundaries, as set by Belgian astronomer
Eugène Delporte
Eugene is a common male given name that comes from the Greek εὐγενής (''eugenēs''), "noble", literally "well-born", from εὖ (''eu''), "well" and γένος (''genos''), "race, stock, kin".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 fund ...
, 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 paired w ...
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 the ...
coordinates are between and .
Covering 506 square degrees or 0.921% of the sky, it ranks 31st of the 88 constellations in size. It can be seen at latitudes between +90° and -60° and is best visible at 9 p.m. during the month of March. Cancer borders the bright constellations of
Leo,
Gemini
Gemini may refer to:
Space
* Gemini (constellation), one of the constellations of the zodiac
** Gemini in Chinese astronomy
* Project Gemini, the second U.S. crewed spaceflight program
* Gemini Observatory, consisting of telescopes in the Norther ...
and
Canis Minor. Under city skies, Cancer is invisible to the naked eye.
Features
Stars
Cancer is the second dimmest of the
zodiacal constellations
The zodiac is a belt-shaped region of the sky that extends approximately 8° north or south (as measured in celestial latitude) of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. The path ...
, having only two stars above the fourth magnitude.
The German cartographer
Johann Bayer 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 , whic ...
through
Omega
Omega (; capital: Ω, lowercase: ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and final letter in the Greek alphabet. In the Greek numeric system/isopsephy (gematria), it has a value of 800. The wo ...
to label the most prominent stars in the constellation, followed by the letter A, then lowercase b, c and d. Within the constellation's borders, there are 104 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 li ...
6.5.
![CancerCC cropped](https://upload.wikimedia.org/wikipedia/commons/8/8a/CancerCC_cropped.jpg)
Also known as Altarf or Tarf,
Beta Cancri is the brightest star in Cancer at
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 li ...
3.5.
Located 290 ± 30
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 from Earth,
it 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 wh ...
system, its main component an
orange giant
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 ...
of spectral type K4III that is varies slightly from a baseline magnitude of 3.53—dipping by 0.005 magnitude over a period of 6 days.
An aging star, it has expanded to around 50 times the Sun's diameter and shines with 660 times its luminosity. It has a faint magnitude 14
red dwarf
''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 ...
companion located 29 arcseconds away that takes 76,000 years to complete an orbit.
Altarf represents a part of Cancer's body.
At magnitude 3.9 is
Delta Cancri
Delta Cancri (δ Cancri, abbreviated Delta Cnc, δ Cnc) is a double star about 180 light-years from the Sun in the constellation of Cancer.
Its two main constituents are designated Delta Cancri A and B. A is itself a binary star whose co ...
, also known as Asellus Australis.
Located 131±1 light-years from Earth,
it is an orange-hued giant star that has swollen and cooled off the main sequence to become an orange giant with a radius 11 times and luminosity 53 times that of the Sun.
Its common name means "southern donkey".
The star also holds a record for the longest name, "Arkushanangarushashutu," derived from ancient Babylonian language, which translates to "the southeast star in the Crab." Delta Cancri also makes it easy to find
X Cancri, the reddest star in the sky. Known as Asellus Borealis "northern donkey",
Gamma Cancri is a white-hued A-type subgiant of spectral type A1IV and magnitude 4.67,
that is 35 times as luminous as of the Sun.
It is located 181 ± 2 light-years from Earth.
Iota Cancri is a wide double star. The primary is a yellow-hued G-type bright giant star of magnitude 4.0,
located 330 ± 20 light-years from Earth.
It spent much of its stellar life as a B-type main sequence star before expanding and cooling to its current state as it spent its core hydrogen. The secondary is a
white main sequence star of spectral type A3V and magnitude 6.57. Despite having different distances when measured by the HIPPARCOS satellite, the two stars share a common proper motion and appear to be a natural binary system.
Located 181 ± 2
light-years
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 ...
from Earth,
Alpha Cancri (Acubens) is a multiple star with a primary component an apparent white main sequence star of spectral type A5 and magnitude 4.26. The secondary is of magnitude 12.0 and is visible in small amateur
telescopes
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...
. Its common name means "the claw".
The primary is actually two very similar white main sequence stars that are 5.3 AU distant from each other and the secondary is two small main sequence stars, most likely red dwarfs, that are 600 AU from the main pair. Hence the system is a quadruple one.
Zeta Cancri or Tegmine ("the shell") is a
multiple star system
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a '' star cluster'' or '' galaxy'', although, broadly speaki ...
that contains at least four stars located 82 light-years from Earth. The two brightest components are a binary star with 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 1100 years; the brighter component is a yellow-hued binary pair and the dimmer component is a yellow-hued star of magnitude 6.2. The brighter component is itself a binary star with a period of 59.6 years; its primary is of magnitude 5.6 and its secondary is of magnitude 6.0. This pair is at its greatest separation around 2019.
Ten star systems have been found to have planets. Rho-1 Cancri or
55 Cancri (or Copernicus
) is a binary star approximately 40.9 light-years distant from Earth. 55 Cancri consists of a yellow dwarf and a smaller red dwarf, with five planets orbiting the primary star; one low-mass planet that may be either a hot, water-rich world or a carbon planet and four gas giants. 55 Cancri A, classified as a rare "super metal-rich" star, is one of the top 100 target stars for NASA's Terrestrial Planet Finder mission, ranked 63rd on the list. The red dwarf 55 Cancri B, a suspected binary, appears to be gravitationally bound to the primary star, as the two share common proper motion.
YBP 1194
YBP 1194 is a G-type main-sequence star, class G5V, in the open cluster M67 in the constellation Cancer. It is the best solar twin found to date, having the near exact temperature and mass as the Sun. YBP 1194 has a higher metallicity ...
is a sunlike star in the open cluster
M67 that has been found to have three planets.
Deep-sky objects
![Messier 44 2018](https://upload.wikimedia.org/wikipedia/commons/9/94/Messier_44_2018.jpg)
Cancer is best known among stargazers as the home of
Praesepe
The Beehive Cluster (also known as Praesepe (Latin for "manger" or "crib"), M44, NGC 2632, or Cr 189), is an open cluster in the constellation Cancer. One of the nearest open clusters to Earth, it contains a larger population of stars than other ...
(Messier 44), an
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, and ...
also called the ''Beehive Cluster'', located right in the centre of the constellation. Located about 590 light-years from Earth, it is one of the nearest open clusters to our Solar System. M 44 contains about 50 stars, the brightest of which are of the sixth magnitude. Epsilon Cancri is the brightest member at magnitude 6.3. Praesepe is also one of the larger open clusters visible; it has an area of 1.5 square degrees, or three times the size of the full Moon.
It is most easily observed when Cancer is high in the sky. North of the Equator, this period stretches from February to May.
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 ...
described the Beehive Cluster as "the nebulous mass in the breast of Cancer." It was one of the first objects
Galileo
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He was ...
observed with his telescope in 1609, spotting 40 stars in the cluster. Today, there are about 1010 high-probability members, most of them (68 percent) red dwarfs. The Greeks and Romans identified the nebulous object as a manger from which two donkeys, represented by the neighbouring stars
213Asellus Borealis and
210Asellus Australis, were eating. The stars represent the donkeys that the god
Dionysus
In ancient Greek religion and myth, Dionysus (; grc, Διόνυσος ) is the god of the grape-harvest, winemaking, orchards and fruit, vegetation, fertility, insanity, ritual madness, religious ecstasy, festivity, and theatre. The Romans ...
and his tutor
Silenus
In Greek mythology, Silenus (; grc, Σειληνός, Seilēnós, ) was a companion and tutor to the wine Greek god, god Dionysus. He is typically older than the satyrs of the Dionysian retinue (''thiasos''), and sometimes considerably older, ...
rode in the war against the
Titans. The ancient Chinese interpreted the object as a ghost or demon riding in a carriage, calling it a "cloud of pollen blown from under willow catkins."
The smaller, denser open cluster
Messier 67 can also be found in Cancer, 2600 light-years from Earth. It has an area of approximately 0.5 square degrees, the size of the full Moon. It contains approximately 200 stars, the brightest of which are of the tenth magnitude.
QSO J0842+1835 is a
quasar used to measure the
speed of gravity
In classical theories of gravitation, the changes in a gravitational field propagate. A change in the distribution of energy and momentum of matter results in subsequent alteration, at a distance, of the gravitational field which it produces. In ...
in
VLBI
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth or in space. T ...
experiment conducted by
Edward Fomalont and
Sergei Kopeikin
Sergei Kopeikin (born April 10, 1956) is a USSR-born theoretical physicist and astronomer presently living and working in the United States, where he holds the position of Professor of Physics at the University of Missouri in Columbia, Missouri. ...
in September 2002.
OJ 287
OJ 287 is a BL Lac object 3.5 billion light-years from Earth that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891. Seen on photographic plates since at least 18 ...
is a
BL Lacertae object
A BL Lacertae object or BL Lac object is a type of active galactic nucleus (AGN) or a galaxy with such an AGN, named after its prototype, BL Lacertae. In contrast to other types of active galactic nuclei, BL Lacs are characterized by rapid and l ...
located 3.5
billion
Billion is a word for a large number, and it has two distinct definitions:
*1,000,000,000, i.e. one thousand million, or (ten to the ninth power), as defined on the short scale. This is its only current meaning in English.
* 1,000,000,000,000, i. ...
light years
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 ...
away that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891. It was first detected at radio wavelengths during the course of the
Ohio Sky Survey
The Ohio Sky Survey was an astronomical survey of extragalactic radio sources. Data were taken between 1965 and 1971 using the Big Ear radio telescope at the Ohio State University Radio Observatory (OSURO), also known as the "Big Ear Radio Observ ...
. Its central
supermassive black hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical ob ...
is
among the largest known, with a mass of 18 billion
solar masses
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 of ...
, more than six times the value calculated for the previous largest object.
History and mythology
Cancer was first recorded by
Claudius 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 importance ...
in the in ''The
Mathematical Syntaxis'' (a.k.a. ''
Almagest
The ''Almagest'' is a 2nd-century Greek-language mathematical and astronomical treatise on the apparent motions of the stars and planetary paths, written by Claudius Ptolemy ( ). One of the most influential scientific texts in history, it canoni ...
''), under the Greek name (''Karkinos'').
In the late 1890s,
R.H. Allen asserted the following, with no supporting citation:
:"Cancer is said to have been the place for the
Akkad Akkad may refer to:
*Akkad (city), the capital of the Akkadian Empire
*Akkadian Empire, the first ancient empire of Mesopotamia
*Akkad SC, Iraqi football club
People with the name
*Abbas el-Akkad, Egyptian writer
*Abdulrahman Akkad, Syrian LGBT act ...
ian ''Sun of the South'', perhaps from its position at the
winter solstice
The winter solstice, also called the hibernal solstice, occurs when either of Earth's poles reaches its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere ( Northern and Southern). For that hemisphere, the winte ...
in very remote antiquity; but afterwards it was associated with the fourth month ''
Duzu'' , our June–July, and was known as the ''Northern Gate of Sun'' ..."
Very few of Cancer's stars are
visible to the naked eye, and its brightest stars are only 4th
magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
. Cancer was often considered the "Dark Sign", quaintly described as "black and without eyes".
Dante
Dante Alighieri (; – 14 September 1321), probably baptized Durante di Alighiero degli Alighieri and often referred to as Dante (, ), was an Italian poet, writer and philosopher. His ''Divine Comedy'', originally called (modern Italian: '' ...
, alluded to its faintness in ''
Paradiso'', and mentioned it being visibility for the whole night when it
culminated at midnight in a Northern Hemisphere winter month:
:Then a light among them brightened,
:so that, if Cancer one such crystal had,
:winter would have a month of only a day.
Cancer was the backdrop to the Sun's most northerly position in the sky (the
summer solstice
The summer solstice, also called the estival solstice or midsummer, occurs when one of Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere ( Northern and Southern). For that hemisphere, the summer ...
) in ancient times, when the Earth's Sun-facing side was maximally tilted towards the south, in the
Gregorian calendar
The Gregorian calendar is the calendar used in most parts of the world. It was introduced in October 1582 by Pope Gregory XIII as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years dif ...
kept within a few days of June 21. Equivalently, this is the date when the Sun is directly overhead as far north as
23.437° N. The northern-most
parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of ...
where the sun is directly overhead is still called the ''
Tropic of Cancer
The Tropic of Cancer, which is also referred to as the Northern Tropic, is the most northerly circle of latitude on Earth at which the Sun can be directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted toward ...
'', even though the corresponding position on the sky now occurs in
Taurus
Taurus is Latin for 'bull' and may refer to:
* Taurus (astrology), the astrological sign
* Taurus (constellation), one of the constellations of the zodiac
* Taurus (mythology), one of two Greek mythological characters named Taurus
* '' Bos tauru ...
, due to the
precession of the equinoxes
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis. In the absence of precession, the astronomical body's orbit would show axial parallelism. In particu ...
.
The close
conjunction
Conjunction may refer to:
* Conjunction (grammar), a part of speech
* Logical conjunction, a mathematical operator
** Conjunction introduction, a rule of inference of propositional logic
* Conjunction (astronomy), in which two astronomical bodies ...
of Jupiter and Saturn in 1563 – which was observed by
Tycho Brahe
Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was k ...
and led him to note the inaccuracy of existing ephemerides and to begin his own program of astronomical measurements – occurred in Cancer not far from Praesepe.
In
Greek mythology
A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...
, Cancer is identified with the crab that appeared while
Heracles
Heracles ( ; grc-gre, Ἡρακλῆς, , glory/fame of Hera), born Alcaeus (, ''Alkaios'') or Alcides (, ''Alkeidēs''), was a divine hero in Greek mythology, the son of Zeus and Alcmene, and the foster son of Amphitryon.By his adoptive ...
fought the many-headed
Lernaean Hydra
The Lernaean Hydra or Hydra of Lerna ( grc-gre, Λερναῖα Ὕδρα, ''Lernaîa Hýdra''), more often known simply as the Hydra, is a snake, serpentine water monster in Greek mythology, Greek and Roman mythology. Its lair was the lake of Le ...
. Hercules slew the crab after it bit him in the foot. Afterwards, the goddess
Hera
In ancient Greek religion, Hera (; grc-gre, Ἥρα, Hḗrā; grc, Ἥρη, Hḗrē, label=none in Ionic and Homeric Greek) is the goddess of marriage, women and family, and the protector of women during childbirth. In Greek mythology, she ...
, an enemy of Heracles, placed the crab among the stars.
Illustrations
![Sidney Hall - Urania's Mirror - Cancer](https://upload.wikimedia.org/wikipedia/commons/c/ce/Sidney_Hall_-_Urania%27s_Mirror_-_Cancer.jpg)
The modern symbol for Cancer represents the pincers of a
crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
, but Cancer has been represented as many types of creatures, usually those living in the water, and always those with an
exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...
.
In the Egyptian records of about 2000 BC it was described as Scarabaeus (
Scarab), the sacred
emblem
An emblem is an abstract or representational pictorial image that represents a concept, like a moral truth, or an allegory, or a person, like a king or saint.
Emblems vs. symbols
Although the words ''emblem'' and '' symbol'' are often use ...
of immortality. In Babylonia the constellation was known as MUL.AL.LUL, a name which can refer to both a crab and a snapping turtle. On boundary stones, the image of a turtle or tortoise appears quite regularly and it is believed that this represents Cancer since a conventional crab has not so far been discovered on any of these monuments.
There also appears to be a strong connection between the Babylonian constellation and ideas of death and a passage to the underworld, which may be the origin of these ideas in later Greek myths associated with Hercules and the Hydra.
In the 12th century, an illustrated astronomical manuscript shows it as a
water beetle
A water beetle is a generalized name for any beetle that is adapted to living in water at any point in its life cycle. Most water beetles can only live in fresh water, with a few marine species that live in the intertidal zone or littoral zone. Th ...
.
Albumasar
Abu Ma'shar al-Balkhi, Latinized as Albumasar (also ''Albusar'', ''Albuxar''; full name ''Abū Maʿshar Jaʿfar ibn Muḥammad ibn ʿUmar al-Balkhī'' ;
, AH 171–272), was an early Persian Muslim astrologer, thought to be the greatest as ...
writes of this sign in ''Flowers of Abu Ma'shar''. A 1488
Latin
Latin (, or , ) is a classical language belonging to the 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 the power of the ...
translation depicts cancer as a large
crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
,
which also is the constellation's name in most
Germanic languages
The Germanic languages are a branch of the Indo-European language family spoken natively by a population of about 515 million people mainly in Europe, North America, Oceania and Southern Africa. The most widely spoken Germanic language, Engli ...
.
Jakob Bartsch
Jakob Bartsch or Jacobus Bartschius (c. 1600 – 26 December 1633) was a German astronomer.
Biography
Bartsch was born in Lauban (Lubań) in Lusatia. He was taught how to use the astrolabe by Sarcephalus (Christopher Hauptfleisch), a librar ...
and
Stanislaus Lubienitzki, in the 17th century, described it as a
lobster
Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...
.
Names
R.H. Allen, in
''Star Names: Their lore and meanings'', lists names for the constellation as follows:
:In
Ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...
,
Aratus
Aratus (; grc-gre, Ἄρατος ὁ Σολεύς; c. 315 BC/310 BC240) was a Greek didactic poet. His major extant work is his hexameter poem ''Phenomena'' ( grc-gre, Φαινόμενα, ''Phainómena'', "Appearances"; la, Phaenomena), the ...
called the crab (''Karkinos''), which was followed by
Hipparchus
Hipparchus (; el, Ἵππαρχος, ''Hipparkhos''; BC) was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the equi ...
and
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 ...
. The
Alfonsine tables called it ''Carcinus'', a Latinized form of the Greek word.
Eratosthenes
Eratosthenes of Cyrene (; grc-gre, Ἐρατοσθένης ; – ) was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria ...
extended this as , , (''Karkinos'', ''Onoi'', ''kai Fatne''): the Crab, Asses, and Crib. In
Ancient Rome
In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 B ...
,
Manilius
The gens Manilia was a plebeian family at ancient Rome. Members of this gens are frequently confused with the Manlii, Mallii, and Mamilii. Several of the Manilii were distinguished in the service of the Republic, with Manius Manilius obtaini ...
and
Ovid
Pūblius Ovidius Nāsō (; 20 March 43 BC – 17/18 AD), known in English as Ovid ( ), was a Roman poet who lived during the reign of Augustus. He was a contemporary of the older Virgil and Horace, with whom he is often ranked as one of the th ...
called the constellation ''Litoreus'' (shore-inhabiting). ''Astacus'' and ''Cammarus'' appear in various classic writers, while it is called ''Nepa'' in
Cicero
Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, and academic skeptic, who tried to uphold optimate principles during the political crises that led to the estab ...
's ''
De Finibus
''De finibus bonorum et malorum'' ("On the ends of good and evil") is a Socratic dialogue by the Ancient Rome, Roman orator, politician, and Academic skepticism, Academic Skeptic philosopher Marcus Tullius Cicero. It consists of three dialogues, ...
'' and the works of
Columella
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire.
His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...
,
Plautus
Titus Maccius Plautus (; c. 254 – 184 BC), commonly known as Plautus, was a Roman playwright of the Old Latin period. His comedies are the earliest Latin literary works to have survived in their entirety. He wrote Palliata comoedia, the gen ...
, and
Varro
Marcus Terentius Varro (; 116–27 BC) was a Roman polymath and a prolific author. He is regarded as ancient Rome's greatest scholar, and was described by Petrarch as "the third great light of Rome" (after Vergil and Cicero). He is sometimes calle ...
; all of these words signify a crab,
lobster
Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...
, or
scorpion
Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always end ...
.
:
Athanasius Kircher
Athanasius Kircher (2 May 1602 – 27 November 1680) was a German Jesuit scholar and polymath who published around 40 major works, most notably in the fields of comparative religion, geology, and medicine. Kircher has been compared to fe ...
said that in Coptic Egypt it was (''Klaria''), the ''Bestia seu Statio
Typhon
Typhon (; grc, Τυφῶν, Typhôn, ), also Typhoeus (; grc, Τυφωεύς, Typhōeús, label=none), Typhaon ( grc, Τυφάων, Typháōn, label=none) or Typhos ( grc, Τυφώς, Typhṓs, label=none), was a monstrous serpentine giant an ...
is'' (the Power of Darkness).
Jérôme Lalande
Joseph Jérôme Lefrançois de Lalande (; 11 July 1732 – 4 April 1807) was a French astronomer, freemason and writer.
Biography
Lalande was born at Bourg-en-Bresse (now in the département of Ain) to Pierre Lefrançois and Marie‐Anne‐Gab ...
identified this with
Anubis
Anubis (; grc, Ἄνουβις), also known as Inpu, Inpw, Jnpw, or Anpu in Ancient Egyptian () is the god of death, mummification, embalming, the afterlife, cemeteries, tombs, and the Underworld, in ancient Egyptian religion, usually depict ...
, one of the Egyptian divinities commonly associated with
Sirius
Sirius is the list of brightest stars, brightest star in the night sky. Its name is derived from the Ancient Greek language, Greek word , or , meaning 'glowing' or 'scorching'. The star is designated α Canis Majoris, Latinisation ...
.
[
:The Indian language ]Sanskrit
Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...
shares a common ancestor with Greek, and the Sanskrit name of Cancer is ''Karka'' and ''Karkata''. In Telugu
Telugu may refer to:
* Telugu language, a major Dravidian language of India
*Telugu people, an ethno-linguistic group of India
* Telugu script, used to write the Telugu language
** Telugu (Unicode block), a block of Telugu characters in Unicode
S ...
it is ''"Karkatakam"'', in Kannada
Kannada (; ಕನ್ನಡ, ), originally romanised Canarese, is a Dravidian language spoken predominantly by the people of Karnataka in southwestern India, with minorities in all neighbouring states. It has around 47 million native s ...
''"Karkataka"'' or ''"Kataka"'', in Tamil
Tamil may refer to:
* Tamils, an ethnic group native to India and some other parts of Asia
**Sri Lankan Tamils, Tamil people native to Sri Lanka also called ilankai tamils
**Tamil Malaysians, Tamil people native to Malaysia
* Tamil language, nativ ...
''Karkatan'', and in Sinhala . The later Hindus knew it as ''Kulira'', from the Greek (''Kolouros''), the term originated by Proclus
Proclus Lycius (; 8 February 412 – 17 April 485), called Proclus the Successor ( grc-gre, Πρόκλος ὁ Διάδοχος, ''Próklos ho Diádokhos''), was a Greek Neoplatonist philosopher, one of the last major classical philosophers ...
.[
]
Astrology
, the Sun appears in the constellation Cancer from July 20 – August 9. In tropical astrology
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
, the Sun is considered to be in the ''sign'' of Cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
from June 22 – July 22, and in sidereal astrology
'' Sidereal'' and ''tropical'' are terms used to describe two different definitions of a year, applied in sidereal solar calendars or tropical solar calendars. In astrology, they refer to two different systems of ecliptic coordinates used to d ...
, from July 16 – August 16.
Equivalents
In 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 twe ...
, the stars of Cancer lie within the Vermilion Bird of the South (南方朱雀, ''Nán Fāng Zhū Què'').
See also
* Cancer (Chinese astronomy) According to traditional Chinese uranography, the modern constellation Cancer is located within the southern quadrant of the sky, which is symbolized as the Vermilion Bird of the South (南方朱雀, ''Nán Fāng Zhū Què'').
The name of the wes ...
Notes
References
Bibliography
* Reprinted as
*
*
*
*
External links
The Deep Photographic Guide to the Constellations: Cancer
Warburg Institute Iconographic Database (medieval and early modern images of Cancer)
{{DEFAULTSORT:Cancer (Constellation)
Northern constellations
Constellations listed by Ptolemy
Mythological arthropods