Castor

From Slackerpedia Galactica

Castor is one of the two bright stars in the constellation Gemini. The other is Pollux. These two stars are the heads of the twins. With a small telescope, one can tell them apart easily. Castor is a double star and Pollux isn't. So one just doesn't have to remember that it's the one on the right from the Northern Hemisphere. Pollux isn't jealous though, because it has at least one extrasolar planet.