ASTRAEUS

a Titan and son of Crius and Eurybia. By Eos he became the father of the winds Zephyrus, Boreas, and Notus, Eosphorus (the morning star), and all the stars of heaven. (Theogony of Hesiod 376)

Ovid ( Metamorphoses by Ovid xiv) calls the winds fratres Astraei, which does not mean that they were brothers of Astraeus, but brothers through Astraeus, their common father.