Canis Major

CMa · genitive Canis Majoris · southern sky

The Canis Major figure as the IAU defines it, drawn looking south with east to the left — the orientation you see standing outside.

At a glance

Catalogued stars
148
Visible to the eye
148 stars
Brightest star
Sirius (-1.46)
Best seen
December
Declination span
-30.1° to -12.0°
Nearest star
Sirius · 8.6 ly

Visible from everywhere south of about 60°N.

When and where to look for Canis Major

Canis Major crosses the meridian — its highest point in the sky — at local midnight around December, which makes the months from November to January the easiest time to find it in the evening. It spans declinations -30.1° to -12.0°, so visible from everywhere south of about 60°N.

The quickest way to find it is to open the live AR sky map and point your phone at the sky — if Canis Major is above your horizon right now, its figure is drawn in the position it genuinely occupies above you.

Brightest stars in Canis Major

StarMagTypeDistance
SiriusAlpha Canis Majoris-1.46A1V8.6 ly
Adhara21Eps CMa1.50B2II405.2 ly
Wezen25Del CMa1.83F8Ia1,606.7 ly
Mirzam2Bet CMa1.98B1II/III492.7 ly
Aludra31Eta CMa2.45B5Ia1,988.8 ly
Furud1Zet CMa3.02B2.5V362.4 ly

Magnitude runs backwards: lower numbers are brighter, and anything below about 6.5 is beyond the naked eye under a dark sky.

What Canis Major is made of

The catalogue lists 148 stars within Canis Major, of which 148 are magnitude 6.5 or brighter — the limit of what an unaided eye picks up under a genuinely dark sky. The rest need binoculars or a telescope.

Spectral make-up

O2
B64
A19
F14
G8
K35
M6

Spectral class is a temperature ordering, running from O at around 30,000 K down to M below 3,500 K. A constellation is a direction, not a group, so this is simply what happens to lie along that line of sight.

The closest catalogued star in this direction is Sirius at 8.6 light years. The most distant is HD 53974 at roughly 3,048 light years — stars that appear side by side here are nothing of the sort.

Nearby constellations