The twenty-eight lunar mansions

The twenty-eight xiu, or lunar mansions, divide the Chinese sky along the celestial equator, each named for an asterism and marking a station of the Moon's monthly path. They are grouped into four palaces of seven mansions each, presided over by the four celestial animals: the Azure Dragon of the east, the Vermilion Bird of the south, the White Tiger of the west and the Black Tortoise of the north.

They are among the oldest features of Chinese astronomy, attested from early antiquity, and served both to track the heavens and, in the divinatory tradition, to assign qualities to days and directions.