- Canis Major
name = Canis major
abbreviation = CMa
genitive = Canis Majoris
symbology = the greater dog
RA = 7
areatotal = 380
arearank = 43rd
numbermainstars = 8
numberbfstars = 32
numberstarsplanets = 2
numberbrightstars = 5
numbernearbystars = 1
starmagnitude = −1.46
neareststarname = Sirius (α CMa)
stardistance = 8.6
numbermessierobjects = 1
meteorshowers = None
latmax = 60
latmin = 90
month = February
Canis Major (pron-en|ˌkeınɨs ˈmeıdʒɚ, _la. greater
dog) is one of the 88 modern constellations, and was also in Ptolemy's list of 48 constellations. It is said to represent one of the dogs following Orion the hunter (see also the constellations of Orion, Canis Minor, and Canes Venatici.) Canis Major contains Sirius, the brightest star in the night sky, and that star is part of what is called the Winter Trianglein the Northern Hemisphere, or the Summer Triangle in the Southern.
Canis Major's alpha star,
Sirius, is the brightest object in the sky (besides the Sun, Moon, Jupiter, and Venus) as seen from Earth. It is also one of the nearest. The star's name means "scorching", since the summer heat occurred just after Sirius' heliacal rising. The Ancient Greeks referred to such times in the summer as "dog days", as only dogs would be mad enough to go out in the heat, leading to the star being known as the "Dog Star". Consequently, the constellation was named after it, as a "Big Dog". Other than that, the largest star known, VY Canis Majoris, is also found in this constellation.
There are several other fairly bright stars in Canis Major, all with Arabic names:
*β CMa: (1.98v)
Murzim- The Announcer
*γ CMa: (4.11)
*δ CMa: (1.83)
Wezen- The Weight
*ε CMa: (1.51v)
*ζ CMa: (3.02)
Furud- Bright Single One
*η CMa: (2.45v)
Aludra- the virginMuliphen is the Arabic rendering of the Greek for "dog's ear".
Notable deep sky objects
There are not many bright
deep sky objects in this region of sky. The only Messier objectin Canis Major is Messier 41(NGC 2287), an open clusterof visual magnitude4.6. It is located about 4 degrees directly south of Sirius. Messier 41 is roughly 2350 light years away from Earth, contains about 8,000 stars, and is about 24 light years in diameter. It is also noted for containing a number of K-class stars.
The band of the
Milky Waygoes through Canis Major and therefore background galaxies are hidden behind interstellar dust clouds. However, in 2003, Canis Major Dwarf, the closest satellite galaxyto Earth was found within the constellation.
Also the star
VY Canis Majoris(VY CMa) is a red hypergiant star in Canis Major. It is the largest known star and also one of the most luminous known. It is located about 1.5 kiloparsecs (or 5,000 light-years) from Earth.
This constellation was known to the easterners from the time
immemorial. In early European classical days, this constellation represented Laelaps, gift from Zeusto Europa; or sometimes the hound of Procris, Diana's nymph; or the one given by Aurora to Cephalus, so famed for its speed that Zeuselevated it to the sky. Most commonly, Canis Major is Orion's hunting dog, pursuing Lepus the Hareor helping Orion fight Taurus the Bull, and is referred to in this way by Aratos, Homerand Hesiod. The ancient Greeks refer only to one dog, but by Roman times, Canis Minorappears as Orion's second child.
Roman myth also refers to Canis Major as "
Custos Europae", the dog guarding Europa but failing to prevent her abduction by Jupiter in the form of a bull; and as "Janitor Lethaeus", the watchdog of Hell.
Depending on the faintness of stars considered, Canis Major resembles a dog facing either above or below the
ecliptic. When facing below, since Sirius was considered a dog in its own right, early Greek mythology sometimes considered it to be two headed. As such, together with the area of the sky that is deserted (now considered as the new and extremely faint constellations Camelopardalisand Lynx), and the other features of the area in the Zodiacsign of Gemini (i.e. the Milky Way, and the constellations Gemini, Orion, Auriga, and Canis Minor), this may be the origin of the myth of the cattle of Geryon, which forms one of The Twelve Laboursof Heracles. Sirius was an object of wonder and veneration to all ancient peoples throughout human history. In the ancient Vedas this star was known as the Chieftain's star; in other Hindu writings, it is referred to as Sukra, the Rain God, or Rain Star. The Dog is also described as "he who awakens the gods of the air, and summons them to their office of bringing the rain." Sirius was revered as the Nile Star, or Star of Isis, by the ancient Egyptians. Its annual appearance just before dawn at the Summer Solstice, June 21, heralded the coming rise of the Nile, upon which Egyptian agriculture depended. This helical rising is referred to in many temple inscriptions, where the star is known as the Divine Sepat, identified as the soul of Isis. In the temple of Isis-Hathor at Dedendrah, Egypt, appears the inscription, "Her majesty Isis shines into the temple on New Year's Day, and she mingles her light with that of her father on the horizon." The Arabic word Al Shi'ra resembles the Greek, Roman, and Egyptian names suggesting a common origin in Sanskrit, in which the name Surya, the Sun God, simply means the "shining one."
* Ian Ridpath and Wil Tirion (2007). "Stars and Planets Guide", Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.
* [http://www.allthesky.com/constellations/canismajor/ The Deep Photographic Guide to the Constellations: Canis Major]
* [http://www.ianridpath.com/startales/canismajor.htm Star Tales – Canis Major]
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