Wei, the Tail of the Azure Dragon

Wei, the Tail, is the sixth of the twenty-eight xiu and the sixth mansion of the eastern palace, the Azure Dragon, one of two mansions romanised Wei, this one meaning tail. It marks the tail of the celestial dragon, identified with the curving line of stars in Scorpius. In the later astrological tradition its animal totem is the Tiger. As one of the twenty-eight lunar mansions it tracks a portion of the sky along the Moon's monthly circuit. These are the conventions of the Chinese astronomical and calendrical tradition, in which the twenty-eight xiu, grouped into four palaces of seven, divide the heavens; the Azure Dragon of the east, from Horn to Winnowing Basket, coils across the sector of sky the almanac assigns to spring.

Wei's curving line of tail-stars in Scorpius was read in later Chinese court astrology as marking the boundary of the imperial domain, the dragon's tail region traditionally correlated with frontier and border affairs in the field-allocation system, fenye, that assigned each of the twenty-eight mansions to a corresponding terrestrial region of China; a comet or unusual event observed near a given mansion was read as a portent specifically for the province assigned to it, a technique with no real counterpart in the Indian or Arabic lunar-mansion traditions.