7 main stars, which are dubhe, merak, phecda, megrez, alioth, mizar, and alkaid. ursa major has an asterism, a constelation in a constellation, called big dipper. it was discovered in 1869 by richard a. proctor. in roman mythology, zeus fell in love with callisto, and had a son with her. his wife, Hera, was mad at them and turned callisto into a bear. later on, the son, Arcas, tried to kill Callisto, because he thought she was a normal bear, so Zeus turned him into a bear too, and sent them both into the sky to keep them safe. Callisto becomes Ursa major, and Arcas becomes Ursa minor. in another version, Arcas becomes the bootes constellation instead.