Polydeuces is a companion, or "Trojan" moon of Dione.
Polydeuces was discovered by the Cassini mission team on 21 October 2004.
How Polydeuces Got its Name:
Originally designated S/2004 S5, Polydeuces (another name for Pollux) is named for the son of Leda and Zeus.
John Herschel suggested that the moons of Saturn be associated with mythical brothers and sisters of Kronus. (Kronus is the equivalent of the Roman god Saturn in Greek mythology.) The International Astronomical Union now controls the official naming of astronomical bodies.