Canis Major

Canis Major's first article already ties Sirius to the Egyptian Nile flood. What it has no room for is that Sopdet, the Egyptian name for the star, was not simply an omen but a figure in her own right, paired deliberately with the neighbouring constellation of Orion.

Egyptian star ceilings personify Sopdet as a woman, sometimes as a cow bearing a star between her horns, walking behind or beside Sah, the striding figure at Orion identified with Osiris. The pairing is not incidental: Sah and Sopdet are the two most securely identified figures in the Egyptian decan system, thirty-six star groups used to mark the hours of the night, and their relationship, consort or companion depending on the source, was read as mirroring the relationship between Osiris and Isis, with whom Sopdet came to be identified.

The heliacal rising, the star's first reappearance in the dawn sky after weeks of invisibility, was the calendar event, and it fell close enough to the actual onset of the Nile's annual flood that Egyptian record-keepers used it as the marker for their new year, a practical function bound to a personified figure rather than to an abstract star.

None of this involves the dog at all. The Greek hound following at Orion's heel and the Egyptian goddess accompanying Sah are two completely different relationships built on the same two points of light.

Canis Major, the Greater Dog, is a southern constellation, one of Ptolemy's forty-eight, following at the heel of Orion as one of the hunter's two hounds. It contains Sirius, the brightest star in the entire night sky, known as the Dog Star. In antiquity the heliacal rising of Sirius, its first reappearance in the dawn before the sun, marked the flooding of the Nile for the Egyptians and gave the hot dog days of summer their name. The dog is shown pursuing the hare Lepus or the hunt across the sky. In astronomical tradition the constellation is a pattern of stars rather than a zodiac sign. These are the features of Canis Major as the classical and modern traditions describe it, distinct from any astrological use; Sirius has been among the most watched of all stars across cultures.

Columba, the dove, immediately south of Canis Major, was introduced by Petrus Plancius at the end of the sixteenth century, carved from stars Ptolemy had left as an unformed patch beyond his hound's paws; its dove is usually explained as the bird Noah released from the ark, one of relatively few post-classical constellations to draw its imagery from the Bible rather than from Greek myth or from the instruments of early modern science.