University of Edinburgh

BSL Astronomy Glossary - pollux and castor - definition

Definition: Pollux and Castor are the two brightest stars in the constellation of Gemini. When you look at them in the night sky, Pollux lies to the left, just below Castor and is the brighter of the two. As shown in the video illustration, the constellation Gemini is thought to resemble twins and the stars, Pollux and Castor, represent their two heads. To locate them in the night sky, find the three stars that make up Orion's belt. Just above the hunter's belt, lies the bright star, Betelgeuse, and by continuing this line upwards and to the left, you will encounter Castor and Pollux.