In the astronomical ceiling of the tomb of Seti (KV17) one of the columns is denoted by the figure of Sekhmet wearing the crown of Hathor as below:
What does this signify? Although Sekhmet is sometimes represented wearing the sun disk, it is never with the horns and always with the uraeus. The sun disk between horns is the usual headress of Hathor, not Sekhmet. Why is Sekhmet wearing the crown of Hathor in this particular context?
The Bull was an animal signifying the Sun and the Spring Equinox. It is a wild speculation that whenever Sekhmet-star ( inasmuch as Sirius is Isis, Io, Sothis, Dog-Star) was rising before Ra (Heliacal Rising) in the Spring morning, it signified the given ruler-ship.
You may find some clues in the Dendera Zodiac, perhaps Sekhmet was a presiding Goddess at the time of Seti's reign according to the Egyptian calendar? Seti I lived approximately 1294 BC to 1279 BC. I'm giving clues, not answers, it is way beyond my competence.
Darnell, John Coleman. "The Apotropaic Goddess in the Eye." Studien Zur Altägyptischen Kultur 24 (1997): 35-48.
