The most important of the Decan stars was Sirius. This star was represented by a goddess known as to the Egyptians as Sopdet and to the Greeks as Sothis. She was shown as a woman wearing a crown surmounted by a five-pointed star. Each year the period when Sirius rose above the horizon at dawn coincided with the coming of the inundation. This event also marked the start of the Egyptian year. In the Pyramid Texts, Sopdet is named as a manifestation of the goddess Isis. Later in Egyptian history, Sopdet was equated with the Eye of Ra and the heliacal rising of her star was linked to the myth of the return of the Distant Goddess.
– Egyptian Mythology, Geraldine Pinch