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Canis Major

Canis Major

GenitiveCanis Majoris
Meaning in Englishthe Greater Dog
Right ascension7 h
Visible to latitudeBetween 60° and -90°
Best visibleFebruary
 - Total
Ranked 43th
380 sq. deg.
Number of stars with
apparent magnitude < 3
Brightest star
 - Apparent magnitude
Sirius (α Canis Majoris)
Meteor showersNone
Bordering constellations

Canis Major (the big 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 the Winter Triangle.

Table of contents
1 Notable features
2 Notable deep sky objects
3 Mythology

Notable features

Canis Major's alpha star Sirius is the brightest star besides the Sun as seen from Earth. It is also one of the nearest. The star is referred to as the Dog Star; its name Sirius means scorching.

Other named stars in Canis Major:

Notable deep sky objects

There aren't many bright
deep sky objects in this region of sky. The only Messier object in Canis Major is M41 (NGC 2287), an open cluster of visual magnitude 4.6. It is located about 4 degrees directly south of Sirius.


In early classical days, this constellation represented Laelaps, Acteon's hound; or sometimes the hound of Procris, Diana's nymph; or the one given by Aurora to Cephalus, so famed for its speed that Zeus elevated it to the sky. Most commonly, Canis Major (or perhaps just the star Sirius) is Orion's hunting dog, pursuing Lepus the hare or helping Orion fight Taurus the bull, and is referred to in this way by Aratos, Homer and Hesiod. The ancient Greeks refer only to one dog, but by Roman times, Canis Minor appears as Orion's second dog.

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.

See also: Canis Major (dwarf galaxy)