Castor (Alpha Geminorum) is a prominent, bright star in the constellation Gemini, famous for being a sextuple star system – six stars in three binary pairs – appearing as a single bright point to the naked eye, but revealing its complexity through a telescope, often seen with its brighter “twin” Pollux (Beta Geminorum), representing the heads of the mythical twins in Greek mythology, and is located about 51 light-years away.
