Canis Major is one of the 88 modern constellations, and was included in the 2nd century astronomer Ptolemy's 48 constellations. Its name is Latin for 'greater dog', and is commonly represented as one of the dogs following Orion the hunter (see also Canis Minor the 'lesser dog'). Canis Major contains Sirius, the brightest star in the night sky, known as the 'dog star', which is part of the asterism known as the Winter Triangle in the Northern Hemisphere, or the Summer Triangle in the Southern. The star is also recognized as Canis Major's nose.
| Constellation | |
 List of stars in Canis Major | |
| Abbreviation | CMa |
|---|---|
| Genitive | Canis Majoris |
| Pronunciation | /ˌkeɪnɨs ˈmeɪdʒər/, genitive /ˈkeɪnɨs məˈdʒɒrɨs/ |
| Symbolism | the greater dog |
| Right ascension | 7 h |
| Declination | −20° |
| Quadrant | SQ2 |
| Area | 380 sq. deg. (43rd) |
| Main stars | 8 |
| Bayer/Flamsteed stars | 32 |
| Stars with planets | 4 |
| Stars brighter than 3.00m | 5 |
| Stars within 10.00 pc (32.62 ly) | 1 |
| Brightest star | Sirius (α CMa) (−1.46m) |
| Nearest star | Sirius (α CMa) (8.60 ly, 2.64 pc) |
| Messier objects | 1 |
| Meteor showers | None |
| Bordering constellations | Monoceros Lepus Columba Puppis |
| Visible at latitudes between +60° and −90°. Best visible at 21:00 (9 p.m.) during the month of February. | |
