Orion, the hunter, is one of the best known constellations in the sky. Orion's belt is formed of three bright stars in a row, from left to right, Alnitak, Alnilam and Mintaka (Zeta, Epsilon and Delta Orionis respectively). At center is the red supergiant Betelgeuse (Alpha Orionis) while at lower center is the white supergiant Rigel (Beta Orionis). Below the belt is the sword of Orion, which contains the Orion nebula (M42).