Pegasus, the Winged Horse

Pegasus is a large, prominent northern constellation, one of Ptolemy's forty-eight, representing the winged horse of Greek myth, born of the blood of the slain Medusa and tamed by the hero Bellerophon. Its most recognisable feature is the Great Square of Pegasus, a large asterism marking the body of the horse, though one of the square's corner stars is now assigned to neighbouring Andromeda. The horse is drawn upside down and incomplete, only its forequarters shown, joined to Andromeda whom Perseus rescued. In astronomical tradition the constellation is a pattern of stars rather than a zodiac sign. These are the features of Pegasus as the classical and modern traditions describe it, distinct from any astrological reading; the Great Square is one of the signposts of the autumn sky, its corner stars also forming lunar-mansion markers in other traditions.

The lunar-mansion marker role noted for the Great Square's corner stars belongs to the Arabic manazil al-qamar, the twenty-eight lunar mansions, a wholly separate system from the Chinese twenty-eight xiu despite the identical count of twenty-eight, and from the twenty-seven Indian nakshatras, three independent traditions of dividing the Moon's monthly path that this atlas treats at length under their own tables.