Eos

Eos was the goddess of the dawn, and the daughter of Hyperion and Theia. She was the sister of Helios (the sun) and Selene (the moon). Her name is the Greek word (eos) which means either 'dawn' or 'east', although one theory suggests that her name could derive from ao, 'to blow', with reference to the cool morning breeze before sunrise.

This is attractively poetic, but possibly smacks more of poetic licence than reality. In some stories Eos is also the name of one of the four horses that drew Helios in his chariot. Eos' Roman equivalent was Aurora.