Canes Venatici

Canes Venatici /ˈkeɪniːz vɪˈnætɪsaɪ/ is one of the 88 official modern constellations. It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for "hunting dogs", and the constellation is often depicted in illustrations as representing the dogs of Boötes the Herdsman, a neighboring constellation. Cor Caroli is the constellation's brightest star, with an apparent magnitude of 2.9. La Superba is one of the reddest stars in the sky and one of the brightest carbon stars. The Whirlpool Galaxy is a spiral galaxy tilted face-on to observers on Earth, and was the first galaxy whose spiral nature was discerned.

Canes Venatici
Constellation
Canes Venatici
AbbreviationCVn
GenitiveCanum Venaticorum
Pronunciation/ˈkeɪniːz vɪˈnætɪsaɪ/ Cánes Venátici, genitive /ˈkeɪnəm vɪnætɪˈkɒrəm/
Symbolismthe Hunting Dogs
Right ascension 12h 06.2m to  14h 07.3m
Declination+27.84° to +52.36°[1]
QuadrantNQ3
Area465 sq. deg. (38th)
Main stars2
Bayer/Flamsteed
stars
21
Stars with planets4
Stars brighter than 3.00m1
Stars within 10.00 pc (32.62 ly)2
Brightest starCor Caroli (Asterion) (α CVn) (2.90m)
Messier objects5
Meteor showersCanes Venaticids
Bordering
constellations
Ursa Major
Boötes
Coma Berenices
Visible at latitudes between +90° and −40°.
Best visible at 21:00 (9 p.m.) during the month of May.

History

Canes Venatici
Canes Venatici depicted in Hevelius's star atlas. Note that, per the conventions of the time, the image is mirrored.
Sidney Hall - Urania's Mirror - Bootes, Canes Venatici, Coma Berenices, and Quadrans Muralis
Canes Venatici can be seen in the orientation they appear to the eyes in this 1825 star chart from Urania's Mirror.

The stars of Canes Venatici are not bright. In classical times, they were listed by Ptolemy as unfigured stars below the constellation Ursa Major in his star catalogue.

In medieval times, the identification of these stars with the dogs of Boötes arose through a mistranslation. Some of Boötes's stars were traditionally described as representing the club (Greek κολλοροβος, kollorobos) of Boötes. When the Greek astronomer Ptolemy's Almagest was translated from Greek to Arabic, the translator Hunayn ibn Ishaq did not know the Greek word and rendered it as a similar-sounding Arabic word for a weapon, writing al-`aşā dhāt al-kullāb (العصا ذات الكلاب), which means "the spearshaft having a hook". When the Arabic text was later translated into Latin, the translator Gerard of Cremona mistook kullāb, meaning "hook", for kilāb (which looks the same in unvowelled Arabic text), meaning "dogs", writing hastile habens canes ("spearshaft having dogs").[2][3][4][5] In 1533, the German astronomer Peter Apian depicted Boötes as having two dogs with him.[6][7]

These spurious dogs floated about the astronomical literature until Hevelius decided to specify their presence in the sky by making them a separate constellation in 1687.[8][9] Hevelius chose the name Asterion (from the Greek 'αστέριον, meaning the "little star",[10] the diminutive of 'αστηρ the "star", or adjective meaning "starry"[11]) 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.[9][12] In his star catalogue, the Czech astronomer Bečvář assigned the names Asterion to β CVn and Chara to α CVn.[13]

Characteristics

Canes Venatici is bordered by Ursa Major to the north and west, Coma Berenices to the south, and Boötes to the east. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is 'CVn'.[14] The official constellation boundaries, as set by Eugène Delporte in 1930, are defined by a polygon of 14 sides. In the equatorial coordinate system, the right ascension coordinates of these borders lie between  12h 06.2m and  14h 07.3m, while the declination coordinates are between +27.84° and +52.36°.[1] Covering 465 square degrees, it ranks 38th of the 88 constellations in size.

Features

CanesVenaticiCC
The constellation Canes Venatici as it can be seen by the naked eye.

Stars

Canes Venatici contains no bright stars, Alpha and Beta Canum Venaticorum being only of 3rd and 4th magnitude respectively. Flamsteed catalogued 25 stars in the constellation, labelling them 1 to 25 Canum Venaticorum, however 1 turned out to be in Ursa Major, 13 was in Coma Berenices and 22 did not exist.[15]

Supervoid

The Giant Void, an extremely large void (part of the universe containing very few galaxies) is within the vicinity of this constellation. It may be possibly the largest void ever discovered, slightly larger than the Eridanus Supervoid and 1,200 times the volume of expected typical voids. It was discovered in 1988 in a deep-sky survey.

Deep-sky objects

Canes Venatici contains five Messier objects, 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.[9] It is a face-on spiral galaxy 37 million light-years from Earth. Widely considered to be one of the most beautiful galaxies visible, M51 has many star-forming regions and nebulae in its arms, coloring them pink and blue in contrast to the older yellow core. M51 has a smaller companion, NGC 5195, that has very few star-forming regions and thus appears yellow. It is passing behind M51 and may be the cause of the larger galaxy's prodigious star formation.[18]

Messier51 sRGB

Messier 51, the Whirlpool Galaxy, photographed by the Hubble Space Telescope.

A cosmic atlas NGC 4248

NGC 4248 is located about 24 million light-years away.[19]

Dim and diffuse

NGC 4242 is a dim galaxy in Canes Venatici.[20]

NGC 4631 HST

NGC 4631 photographed by the Hubble Space Telescope.

NGC 4707 - HST - Potw1651a

Spiral galaxy NGC 4707 lies roughly 22 million light-years from Earth.[21]

Other notable spiral galaxies in Canes Venatici are the Sunflower Galaxy (M63, NGC 5055), M94 (NGC 4736), and M106 (NGC 4258). M63, the Sunflower Galaxy, was named for its appearance in large amateur telescopes. It is a spiral galaxy with an integrated magnitude of 9.0. M94 is a small face-on spiral galaxy with an approximate magnitude of 8.0, about 15 million light-years from Earth.[9] NGC 4631 is a barred spiral galaxy, which is one of the largest and brightest edge-on galaxies in the sky.[22]

M3 (NGC 5272) is a globular cluster 32,000 light-years from Earth. It is 18' in diameter, and at magnitude 6.3 is bright enough to be seen with binoculars. It can even be seen with the naked eye under particularly dark skies.[9]

M94, also classified as NGC 4736, is a face-on spiral galaxy 15 million light-years from Earth. It has very tight spiral arms and a bright core. The outskirts of the galaxy are incredibly luminous in the ultraviolet because of a ring of new stars surrounding the core, 7,000 light-years in diameter. Though astronomers are not sure what has caused this ring of new stars, some hypothesize that it is from shock waves caused by a bar that is thus far invisible.[18]

References

  1. ^ a b "Canes Venatici, Constellation Boundary". The Constellations. International Astronomical Union. Retrieved 15 February 2014.
  2. ^ Allen 1963, p. 105
  3. ^ Kunitzsch 1959, pp. 123–124
  4. ^ Kunitzsch 1974, pp. 227–228
  5. ^ Kunitzsch 1990, pp. 48–49
  6. ^ Apianus 1533
  7. ^ Allen 1963, p. 157
  8. ^ Ridpath, Ian. "Canes Venatici". Star Tales. Retrieved 9 June 2012.
  9. ^ a b c d e f g h i Ridpath 2001, pp. 96–97
  10. ^ Kunitzsch & Smart 2006, p. 22
  11. ^ Allen 1963, p. 115
  12. ^ Hevelius 1690
  13. ^ Bečvář 1951
  14. ^ Russell, Henry Norris (1922). "The New International Symbols for the Constellations". Popular Astronomy. 30: 469–71. Bibcode:1922PA.....30..469R.
  15. ^ Wagman 2003, p. 366.
  16. ^ According to R. H. Allen (Star Names: Their Lore and Meaning), the star was named by Halley for Charles II "at the suggestion of the court physician Sir Charles Scarborough, who said it had shone with special brilliance on the eve of the king's return to London, May 29, 1660". According to Deborah J. Warner (The Sky Explored: Celestial Cartography 1500-1800), it was originally named "Cor Caroli Regis Martyris" ("The Heart of King Charles the Martyr") for Charles I. According to Robert Burnham, Jr. (Burnham's Celestial Handbook, Volume 1), "the attribution of the name to Halley appears in a report published by Johann Bode at Berlin in 1801, but seems to have no other verification".
  17. ^ "V* RS CVn". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 9 June 2012.
  18. ^ a b Wilkins & Dunn 2006
  19. ^ "A cosmic atlas". www.spacetelescope.org. Retrieved 24 July 2017.
  20. ^ "Dim and diffuse". www.spacetelescope.org. Retrieved 17 July 2017.
  21. ^ "Astro-pointillism". www.spacetelescope.org. Retrieved 19 December 2016.
  22. ^ O'Meara, Stephen James: The Caldwell Objects, Sky Publishing Corporation ISBN 0-933346-97-2 page 126
Cited texts
  • Allen, Richard Hinckley (1899), Star Names: Their Lore and Meaning
  • Apianus, Petrus (1533), Horoscopion generale
  • Bečvář, Antonín (1951), Atlas Coeli II - Catalogue 1950.0, Czechoslovak Astronomical Society
  • Hevelius, Johannes (1690), Firmamentum Soviescianum
  • Kunitzsch, P. (1959), Arabische Sternnamen in Europa, Otto Harassowitz
  • Kunitzsch, P. (1974), Der Almagest: Die Syntaxis Mathematica des Claudius Ptolemäus in arabisch-lateinischer Ūberlieferung, Otto Harassowitz
  • Kunitzsch, P. (1990), Der Sternkatalog des Almagest Die arabisch-mittelalterliche Tradition: II Die lateinische Ūbersetzung Gerhards von Cremona, Otto Harassowitz
  • Kunitzsch, P.; Smart, T. (2006), A Dictionary of Modern Star Names: A Short Guide to 254 Star Names and Their Derivations (2nd Revised ed.), Sky Publishing, ISBN 1-931559-44-9
  • Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, Virginia: The McDonald & Woodward Publishing Company. ISBN 978-0-939923-78-6.
  • Wilkins, Jamie; Dunn, Robert (2006), 300 Astronomical Objects: A Visual Reference to the Universe, Firefly Books, ISBN 9781554071753

External links

Coordinates: Sky map 13h 00m 00s, +40° 00′ 00″

Canes Venatici II (dwarf galaxy)

Canes Venatici II or CVn II is a dwarf spheroidal galaxy situated in the Canes Venatici constellation and discovered in 2006 in the data obtained by Sloan Digital Sky Survey. The galaxy is located at the distance of about 150 kpc from the Sun and moves towards the Sun with the velocity of about 130 km/s. It is classified as a dwarf spheroidal galaxy (dSph) meaning that it has an elliptical (ratio of axes ~ 2:1) shape with the half-light radius of about 74+14−10 pc.CVn II is one of the smallest and faintest satellites of the Milky Way—its integrated luminosity is about 8,000 times that of the Sun (absolute visible magnitude of about −4.9), which is much lower than the luminosity of a typical globular cluster. However, its mass is about 2.5 million solar masses, which means that galaxy's mass to light ratio is around 340. A high mass to light ratio implies that CVn II is dominated by the dark matter.The stellar population of CVn II consists mainly of old stars formed more than 12 billion years ago. The metallicity of these old stars is also very low at [Fe/H] ≈ −2.19±0.58, which means that they contain 150 times less heavy elements than the Sun. The stars of CVn II were probably among the first stars to form in the Universe. Currently there is no star formation in CVn II. The measurement have so far failed to detect neutral hydrogen in it—the upper limit is 14000 solar masses.

Canes Venatici I (dwarf galaxy)

Canes Venatici I or CVn I is a dwarf spheroidal galaxy situated in the Canes Venatici constellation and discovered in 2006 in the data obtained by Sloan Digital Sky Survey. It is one of the most distant known satellites of the Milky Way as of 2011 together with Leo I and Leo II. The galaxy is located at a distance of about 220 kpc from the Sun and is moving away from the Sun at a velocity of about 31 km/s. It is classified as a dwarf spheroidal galaxy (dSph) meaning that it has an elliptical (ratio of axes ~ 2.5:1) shape with the half-light radius of about 550 pc.CVn I is a relatively faint satellite of the Milky Way—its integrated luminosity is about 230,000 times that of the Sun (absolute visible magnitude of about −8.6). However, its mass is about 27 million solar masses, which means that the galaxy's mass to light ratio is around 220. A high mass to light ratio implies that CVn I is dominated by the dark matter.The stellar population of CVn I consists mainly of old stars formed more than 10 billion years ago. The metallicity of these old stars is also very low at [Fe/H] ≈ −2.08 ± 0.02, which means that they contain 110 times less heavy elements than the Sun. There are also about 60 RR Lyrae stars. The galaxy also contains a small fraction of younger (1–2 billion years old) more metal-rich ([Fe/H] ≈ −1.5) stars, which account for about 5% of its mass and 10% of its light. These younger stars are concentrated in the center of the galaxy. There is currently no star formation in CVn I and the measurements have so far failed to detect neutral hydrogen in it—the upper limit is 30,000 solar masses.

List of stars in Canes Venatici

This is the list of notable stars in the constellation Canes Venatici, sorted by decreasing brightness.

M94 Group

The M94 Group (Canes Venatici I Group) is a loose, extended group of galaxies located about 13 million light-years away in the constellations Canes Venatici and Coma Berenices. The group is one of many groups that lies within the Virgo Supercluster (i.e. the Local Supercluster) and one of the closest groups to the Local Group.

Although the galaxies in this cluster appear to be from a single large cloud-like structure, many of the galaxies within the group are only weakly gravitationally bound, and some have not yet formed stable orbits around the center of this group. Instead, most of the galaxies in this group appear to be moving with the expansion of the universe.

NGC 4111

NGC 4111 is a lenticular galaxy in the constellation Canes Venatici. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 4111 is about 55,000 light years across. It was discovered by William Herschel in 1788.

NGC 4214

NGC 4214 is a dwarf barred irregular galaxy located around 10 million light-years away in the constellation Canes Venatici.

NGC 4244

NGC 4244, also Caldwell 26, is an edge-on loose spiral galaxy in the constellation Canes Venatici, and is part of the M94 Group or Canes Venatici I Group, a galaxy group relatively close to the Local Group containing the Milky Way.. It is located near the yellow naked-eye star, Beta Canum Venaticorum, but also near the barred spiral galaxy NGC 4151 and irregular galaxy NGC 4214.

At +10.2v or 10.7B magnitude, NGC 4244 lies approximately 4.1 megaparsecs (14 million light years) away. A nuclear star cluster and halo is located near the centre of this galaxy.

NGC 4449

NGC 4449 is an irregular Magellanic type galaxy in the constellation Canes Venatici, being located about 12 million light-years away. It is part of the M94 Group or Canes Venatici I Group that is relatively close to the Local Group hosting our Milky Way galaxy.

NGC 4485

NGC 4485 is an irregular galaxy located in the constellation of Canes Venatici. It is interacting with the spiral galaxy NGC 4490 and as a result both galaxies are distorted and are undergoing intense star formation.

NGC 4490

NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. It lies at a distance of 25 million light years from Earth. It interacts with its smaller companion NGC 4485 and as a result is a starburst galaxy. NGC 4490 and NGC 4485 are collectively known in the Atlas of Peculiar Galaxies as Arp 269. NGC 4490 is located 3/4° northwest of beta Canum Venaticorum and with apparent visual magnitude 9.8, can be observed with 15x100 binoculars. It is a member of Herschel 400 Catalogue. It belongs in Canes Venatici galaxy cloud II.

It was discovered by William Herschel in 1788. Two supernovae have been observed in NGC 4490, SN 1982F, and type II-P SN 2008ax, with peak magnitude 16.1.

NGC 4625

NGC 4625 is a distorted dwarf galaxy in the constellation Canes Venatici. The galaxy is formally classified as a Sm galaxy, which means that its structure vaguely resembles the structure of spiral galaxies. The galaxy is sometimes referred to as a Magellanic spiral because of its resemblance to the Magellanic clouds.

NGC 4627

NGC 4627 is a dwarf elliptical galaxy in the constellation Canes Venatici.

NGC 4707

NGC 4707 is an irregular galaxy in the constellation of Canes Venatici. It was discovered by John Herschel on 5 June 1834, and was described by John Louis Emil Dreyer, the compiler of the New General Catalogue, as a "small, stellar" galaxy.NGC 4707 has a morphological type of Sm or Im, meaning that it is mostly irregular or has very weak spiral arms. The galaxy was imaged by the Hubble Space Telescope in 2016. The image showed that the galaxy had little to no signs of a central bulge or any prominent structures (typical of Magellanic-type spirals). However, the telescope could resolve a large number of stars, as well as several turquoise-colored star forming regions.

NGC 4800

NGC 4800 is a spiral galaxy in the constellation Canes Venatici. It was discovered by William Herschel on Apr 1, 1788.

NGC 5002

NGC 5002 is a Magellanic spiral galaxy in Canes Venatici. It was discovered by Heinrich d'Arrest in 1865. It is also known as MCG 6-29-51, PGC 45728, UGC 8254.It has an apparent size of 1.7 by 1.0 arcmin.

NGC 5003

NGC 5003 is a spiral galaxy in the constellation Canes Venatici. The celestial object was discovered on April 9, 1787, by the German-British astronomer William Herschel.

NGC 5005

NGC 5005 (also known as Caldwell 29) is an inclined spiral galaxy in the constellation Canes Venatici. The galaxy has a relatively bright nucleus and a bright disk that contains multiple dust lanes. The galaxy's high surface brightness makes it an object that is visible to amateur astronomers using large amateur telescopes.

Distance measurements for NGC 5005 vary from 13.7 megaparsecs (45 million light-years) to 34.6 megaparsecs (113 million light-years), averaging about 20 megaparsecs (65 million light-years).

NGC 5112

NGC 5112 is a barred spiral galaxy in the constellation Canes Venatici. This galaxy is in close physical proximity to the edge-on dwarf spiral NGC 5107.

NGC 5223

NGC 5223 is an elliptical galaxy in the constellation of Canes Venatici. It was discovered on 1 May 1785 by William Herschel.

Stars (list)
Star clusters
Galaxies
Galaxy
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Constellation history
Constellations introduced by Johannes Hevelius after 1687
IAU-recognized constellations
Obsolete constellations
(non-IAU constellations)

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