The constellation Pegasus contains at least 16 stars of magnitude 4 or brighter. Three of the four stars in the Great Square belong to Pegasus. Alpheratz, the star at the northeast corner of the square, was designated as the alpha star of the constellation Andromeda.
In addition to the easily recognized pattern of the Great Square, Pegasus contains the deep sky objects M15 as well as NGC 7331, a 10th magnitude spiral galaxy 50 million light years from the Milky Way. Pegasus, which is named after the mythical winged horse, is visible to observers in the Northern Hemisphere before midnight from July through January.