(Ἕσπερος), the evening-star, is called by Hesiod a son of Astraeus and Eos, and was regarded, even by the ancients, as the same as the morning star, whence both Homer and Hesiod call him the bringer of light, ἑωσφόρος (Il. 22.317, 23.226; comp. Plin. Nat. 2.8; Mart. Capell. 8.882, &c., ed. Kopp.) Diodorus (3.60) calls him a son of Atlas, who was fond of astronomy, and once, after having ascended Mount Atlas to observe the stars, he disappeared. He was worshipped with divine honours, and regarded as the fairest star in the heavens. (Eratosth. Catast. 24.) Hyginus (de Sign. Coel. 2) says that some called him a son of Eos and Cephalus. The Romans designated him by the names Lucifer and Hesperus, to characterise him as the morning or evening star.
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890