Pollux

The 17th brightest star in the sky, Pollux is situated with Castor in Gemini, the most northerly and one of the brightest constellations.

Castor appears to the eye as a hot white star, but is actually at least six stars and may be part of an even larger, physically related group of stars.

The names of the stars derive from Graeco-Roman mythology. According to one myth, Castor and Pollux were the children of Zeus and Leda, born after Zeus had seduced Leda when disguised in the form of a swan. In some versions of the myth Leda is represented as having given birth to two eggs. One carried the mortals Castor and Clytaemnestra, the other the gods Pollux and Helen. In other versions of the myth there were only two children of Zeus and in Homer all were said to be the offspring of Leda and the Spartan king Tyndareus.

Castor was depicted as being slain in battle with the sons of Aphareus. On finding his brother's body, Pollux begged Zeus to allow him also to die. According to Homer, Zeus was moved by the depth of their filial love to restore Castor's to life on condition that he and Pollux descended to Hades on alternate days. In other versions of the myth, Zeus is said to have placed the brothers for eternity amongst the stars.

Many cultures have employed these two bright stars at the northern end of the Gemini constellation in sea navigation.