Canes Venatici
Encyclopedia
Canes Venatici is one of the 88 official modern constellation
s. It is a small northern constellation that was created by Johannes Hevelius
in the 17th century. Its name is Latin
for "hunting dog
s", and the constellation is often depicted in illustrations as representing the dogs of Boötes
the Herdsman, a neighboring constellation.
within the constellation Ursa Major
in his star catalogue
. α CVn was Ptolemy's "28th of Ursa Major", and β CVn was his "29th of Ursa Major".
In the medieval times
, the identification of these stars with the dogs of Boötes arose through a mistranslation. Some of Boötes' stars were traditionally described as representing the club
(Greek
, Κολλοροβος) of Boötes. When the Greek astronomer Ptolemy's Almagest
was translated from Greek to Arabic, the translator Johannitius
(following Alberuni) did not know the Greek word and rendered it as the nearest-looking Arabic word, writing العصى ذات الكلاب in ordinary unvowelled Arabic text "al-`aşā dhāt al-kullāb", which means "the spearshaft having a hook". When the Arabic text was translated into Latin
, the translator Gerard of Cremona
(probably in Spain) mistook the Arabic word كلاب for kilāb (the plural of كلب kalb), meaning "dogs", writing hastile habens canes ("spearshaft having dogs").
In 1533, the German astronomer Peter Apian depicted Boötes as having two dogs with him.
These spurious dogs floated about the astronomical literature until Hevelius
decided to specify their presence in the sky by making them a separate constellation. Hevelius chose the name Asterion (from the Greek 'αστέριον, meaning the "little star", the diminutive
of 'αστηρ the "star", or adjective meaning "starry") for the northern dog and Chara (from the Greek χαρά, meaning "joy") for the southern dog, as Canes Venatici, the Hunting Dogs, in his star atlas.
In his star catalogue, the Czech astronomer Becvar
assigned Asterion to β CVn and Chara to α CVn.
respectively.
The constellation's brightest star
is Cor Caroli
(α² CVn), named by Sir Charles Scarborough
in memory of King Charles I
, the deposed king of Britain. It is of magnitude
2.90.
La Superba
(Y CVn) is a semiregular variable star
that varies between magnitudes 4.7 and 6.2 over a period of around 158 days. It is a carbon star
and is famous for being deep red. AM CVn
, a very blue star of magnitude 14, is the prototype of a special class of cataclysmic variable star
s, in which the companion star is a white dwarf
, rather than a main sequence star. RS CVn is the prototype of a special class of binary stars
of chromospherically
active and optically variable
components.
s, including four galaxies
. One of the more significant galaxies in Canes Venatici is the Whirlpool Galaxy
(M51, NGC 5194) and NGC 5195
, a small barred spiral galaxy
that is seen face on. This was the first galaxy recognised as having a spiral structure, this structure being first observed by Lord Rosse
in 1845.
Other notable spiral galaxies in Canes Venatici are the Sunflower Galaxy
(M63, NGC 5055), Messier 94
(NGC 4736), and Messier 106
(NGC 4258).
Messier 3
(NGC 5272) is a globular cluster
. It is 18' in diameter, and at magnitude 6.3 is bright enough to be seen with binoculars
.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
s. It is a small northern constellation that was created by Johannes Hevelius
Johannes Hevelius
Johannes Hevelius Some sources refer to Hevelius as Polish:Some sources refer to Hevelius as German:*Encyplopedia Britannica * of the Royal Society was a councilor and mayor of Danzig , Pomeranian Voivodeship, in the Polish-Lithuanian Commonwealth...
in the 17th century. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "hunting dog
Hunting dog
A hunting dog refers to any dog who assists humans in hunting. There are several types of hunting dogs developed for various tasks. The major categories of hunting dogs include hounds, terriers, dachshunds, cur type dogs, and gun dogs...
s", and the constellation is often depicted in illustrations as representing the dogs of Boötes
Boötes
Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman or plowman...
the Herdsman, a neighboring constellation.
History
The stars of Canes Venatici are not bright. In classical times, they were included by PtolemyPtolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
within the constellation Ursa Major
Ursa Major
Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April...
in his star catalogue
Star catalogue
A star catalogue, or star catalog, is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some...
. α CVn was Ptolemy's "28th of Ursa Major", and β CVn was his "29th of Ursa Major".
In the medieval times
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
, the identification of these stars with the dogs of Boötes arose through a mistranslation. Some of Boötes' stars were traditionally described as representing the club
Club (weapon)
A club is among the simplest of all weapons. A club is essentially a short staff, or stick, usually made of wood, and wielded as a weapon since prehistoric times....
(Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
, Κολλοροβος) of Boötes. When the Greek astronomer Ptolemy's Almagest
Almagest
The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...
was translated from Greek to Arabic, the translator Johannitius
Hunayn ibn Ishaq
Hunayn ibn Ishaq was a famous and influential Assyrian Nestorian Christian scholar, physician, and scientist, known for his work in translating Greek scientific and medical works into Arabic and Syriac during the heyday of the Islamic Abbasid Caliphate.Ḥunayn ibn Isḥaq was the most productive...
(following Alberuni) did not know the Greek word and rendered it as the nearest-looking Arabic word, writing العصى ذات الكلاب in ordinary unvowelled Arabic text "al-`aşā dhāt al-kullāb", which means "the spearshaft having a hook". When the Arabic text was translated into Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, the translator Gerard of Cremona
Gerard of Cremona
Gerard of Cremona was an Italian translator of Arabic scientific works found in the abandoned Arab libraries of Toledo, Spain....
(probably in Spain) mistook the Arabic word كلاب for kilāb (the plural of كلب kalb), meaning "dogs", writing hastile habens canes ("spearshaft having dogs").
In 1533, the German astronomer Peter Apian depicted Boötes as having two dogs with him.
Johannes Hevelius
Johannes Hevelius Some sources refer to Hevelius as Polish:Some sources refer to Hevelius as German:*Encyplopedia Britannica * of the Royal Society was a councilor and mayor of Danzig , Pomeranian Voivodeship, in the Polish-Lithuanian Commonwealth...
decided to specify their presence in the sky by making them a separate constellation. Hevelius chose the name Asterion (from the Greek 'αστέριον, meaning the "little star", the diminutive
Diminutive
In language structure, a diminutive, or diminutive form , is a formation of a word used to convey a slight degree of the root meaning, smallness of the object or quality named, encapsulation, intimacy, or endearment...
of 'αστηρ the "star", or adjective meaning "starry") for the northern dog and Chara (from the Greek χαρά, meaning "joy") for the southern dog, as Canes Venatici, the Hunting Dogs, in his star atlas.
In his star catalogue, the Czech astronomer Becvar
Antonín Bečvář
Antonín Bečvář was a Czech astronomer who was active in Slovakia. He was born in Stará Boleslav. Among his chief achievements is the foundation of the Skalnaté Pleso Observatory and the discovery of the comet C/1947 F2 .Bečvář is particularly important for his star charts: he led the compilation...
assigned Asterion to β CVn and Chara to α CVn.
Stars
Canes Venatici contains no bright stars, α and β CVn being only of 3rd and 4th magnitudeMagnitude (astronomy)
Magnitude is the logarithmic measure of the brightness of an object, in astronomy, measured in a specific wavelength or passband, usually in optical or near-infrared wavelengths.-Background:...
respectively.
The constellation's brightest star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
is Cor Caroli
Cor Caroli
Cor Caroli is the brightest star in the northern constellation Canes Venatici...
(α² CVn), named by Sir Charles Scarborough
Charles Scarborough
Sir Charles Scarborough MP FRS FRCP was an English physician and mathematician.Scarborough was born in St. Martin's-in-the-Fields, London in 1615, the son of Edmund Scarburgh, and was sent to St...
in memory of King Charles I
Charles I of England
Charles I was King of England, King of Scotland, and King of Ireland from 27 March 1625 until his execution in 1649. Charles engaged in a struggle for power with the Parliament of England, attempting to obtain royal revenue whilst Parliament sought to curb his Royal prerogative which Charles...
, the deposed king of Britain. It is of magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
2.90.
La Superba
La Superba
La Superba is a star in the constellation Canes Venatici, well-known for its strikingly red appearance.- Physical characteristics :...
(Y CVn) is a semiregular variable star
Semiregular variable star
Semiregular variable stars are giants or supergiants of intermediate and late spectral type showing considerable periodicity in their light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to more than 2000 days, while the shapes of the light...
that varies between magnitudes 4.7 and 6.2 over a period of around 158 days. It is a carbon star
Carbon star
A carbon star is a late-type star similar to a red giant whose atmosphere contains more carbon than oxygen; the two elements combine in the upper layers of the star, forming carbon monoxide, which consumes all the oxygen in the atmosphere, leaving carbon atoms free to form other carbon compounds,...
and is famous for being deep red. AM CVn
AM Canum Venaticorum
AM Canum Venaticorum is a cataclysmic variable star in the constellation of Canes Venatici. It is the type star of its class of variables, the AM CVn stars....
, a very blue star of magnitude 14, is the prototype of a special class of cataclysmic variable star
Cataclysmic variable star
Cataclysmic variable stars are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state...
s, in which the companion star is a white dwarf
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
, rather than a main sequence star. RS CVn is the prototype of a special class of binary stars
RS Canum Venaticorum variable
RS Canum Venaticorum variables are a type of variable star. They are close binary stars having active chromospheres which can cause large stellar spots. These spots are believed to cause variations in their observed luminosity...
of chromospherically
Chromosphere
The chromosphere is a thin layer of the Sun's atmosphere just above the photosphere, roughly 2,000 kilometers deep....
active and optically variable
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
components.
Deep sky objects
Canes Venatici contains five Messier objectMessier object
The Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets...
s, including four galaxies
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
. One of the more significant galaxies in Canes Venatici is the Whirlpool Galaxy
Whirlpool Galaxy
The Whirlpool Galaxy is an interacting grand-design spiral galaxy that is estimated to be 23 ± 4 million light-years from the Milky Way Galaxy. in the constellation Canes Venatici...
(M51, NGC 5194) and NGC 5195
NGC 5195
NGC 5195 is a dwarf galaxy that is interacting with the Whirlpool Galaxy . Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici...
, a small barred spiral galaxy
Spiral galaxy
A spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as...
that is seen face on. This was the first galaxy recognised as having a spiral structure, this structure being first observed by Lord Rosse
William Parsons, 3rd Earl of Rosse
William Parsons, 3rd Earl of Rosse, Knight of the Order of St Patrick was an Irish astronomer who had several telescopes built. His 72-inch telescope "Leviathan", built 1845, was the world's largest telescope until the early 20th century.-Life:He was born in Yorkshire, England, in the city of...
in 1845.
Other notable spiral galaxies in Canes Venatici are the Sunflower Galaxy
Sunflower Galaxy
The Sunflower Galaxy is a spiral galaxy in the constellation Canes Venatici consisting of a central disc surrounded by many short spiral arm segments...
(M63, NGC 5055), Messier 94
Messier 94
Messier 94 is a spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781,...
(NGC 4736), and Messier 106
Messier 106
Messier 106 is a spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth...
(NGC 4258).
Messier 3
Messier 3
Messier 3 is a globular cluster in the constellation Canes Venatici. It was discovered by Charles Messier in 1764, and resolved into stars by William Herschel around 1784. This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is located at a distance of...
(NGC 5272) is a globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
. It is 18' in diameter, and at magnitude 6.3 is bright enough to be seen with binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
.
External links
- Photographic Catalogue of Deep Sky Objects in Canes Venatici
- The Deep Photographic Guide to the Constellations: Canes Venatici
- Star Tales – Canes Venatici, by Ian RidpathIan RidpathIan William Ridpath is an English science writer and broadcaster made famous for his investigation and explanation of the Rendlesham Forest Incident of December 1980....