Dioscuri

di-os'-ku-ri (Dioscouroi; in Acts 28:11, the King James Version Castor and Pollux, the Revised Version (British and American) THE TWIN BROTHERS; in margin, "Dioscuri"):

The sign of the ship on which Paul sailed from Melita to Syracuse and Rhegium. The Dioscuri (i.e. sons of Zeus), Castor and Pollux, are the two chief stars in the constellation of the Twins. Some 4,000 years BC they served as pointers to mark the beginning of the new year by setting together with the first new moon of springtime. The constellation of the Twins was supposed to be especially favorable to sailors, hence, ships were often placed under the protection of the twin gods.

E. W. Maunder