A crowded six-star system about 50 light-years from Earth. It forms one of the "heads" of the twins of Gemini, and is Gemini's second-brightest star, after nearby Pollux.

Radio Programs

Castor Rare sextuplets among the stars Saturday, March 1, 2014
Castor Three sets of stellar twins Tuesday, January 15, 2013
Castor The twins and triplets of Gemini Monday, May 16, 2011
Moon, Mars, and Gemini A pair of unrelated twins Saturday, November 7, 2009


©2014 The University of Texas McDonald Observatory