Canis Major constellation. Optical image of the constellation Canis Major, the great dog. North is at top. At upper right is Sirius (Alpha Canis Majoris), the brightest star in the sky. It is a white star which lies only 8.6 light years from Earth. At bottom right is the second brightest star in the sky, Canopus (Alpha Carinae), in the constellation Carina, the keel. Canopus lies around 72 light years from Earth. To the left of Canis Major and Carina is the faint constellation Puppis, the poop deck. The Milky Way is seen running from top right to bottom left. This band of light is formed from the millions of stars in the plane of our galaxy.