Canis Major (Latin for Greater Dog) is a constellation. It is also known as the Hunting Dog of Orion.

Mythology and Legends

The ancient Egyptians worshiped Sirius, and built temples to it in the name of Isis. One of the most famous examples is in Denderah, Egypt. Sirius warned them of the rising of floodwaters on the Nile when it appeared above the horizon in the east.

Another legend is that Sirius was a dog given to Cephalos by Aurora. Aurora said that the dog was the fastest hound, and to test this Cephalos had the dog race a fox. The dog was as fast as the fox, and Jupiter was so pleased with the race that he placed Sirius in the sky as a reward.


The star Sirius, also known as the Dog Star, is one of the most visible stars in the sky (magnitude -1.58). It is approximately twenty-seven times brighter than our sun and about twice the diameter. It is 8.7 light-years distant. Sirius is heading towards us at about 5 miles per second.

Sirius has a companion star revolving around it in a highly eccentric path. This companion star is a white dwarf, discovered by Alvan Clark in 1862. This companion has 0.9 times the mass of our sun, but it is 360 times less luminous.

        X M50 Cluster

  Muliphen          Sirius        Murzim
                   /    X M41 Cluster
              * Wezen
             / \
            /   *
           /     \
    Aludra       Adara                 Furad

Lord Tennyson, noted poet, wrote of Sirus:

          The fiery Sirius alters hue,
          And bickers into red and emerald

There was a primitive culture based in Africa called the Dogon, who worshipped the star Sirius. They had symbols representing Sirius and its companion star. Nobody knows how they could have guessed the existance of the white dwarf, since they had no telescopic equipment.
