Castor and Pollux Castor and Pollux Castor and Pollux (or in Greek, Polydeuces) were twin half-brothers in Greek and Roman mythology, known together as the Dioscuri. Their mother was Leda, but they had different fathers; Castor was the mortal son of Tyndareus, the king of Sparta, while Pollux was the divine son of Zeus, who seduced Leda in the guise of a swan. Though accounts of their birth are varied, they are sometimes said to have been born from an egg, along with their twin sisters Helen of Troy and Clytemnestra. In Latin the twins are also known as the Gemini (literally "twins")
Castor (star) Dzira", which was translated into Latin as "Prima Brachii", meaning "the first in the paw". In Chinese, (), meaning "North River", refers to an asterism consisting of Castor, ρ Geminorum, and Pollux. Consequently, Castor itself is known as (, .) In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Castor" for the star α Geminorum Aa. Castor C also has the variable star designation