Di (Root)

Di (Root) is the third of the twenty-eight xiu, the lunar mansions of traditional Chinese astronomy. Each xiu is a segment of the sky marked by a group of stars near the celestial equator, and together they divide the heavens into the belt through which the sun, moon and planets appear to move.

Palace, animal and place in the sky

This mansion belongs to the Azure Dragon of the East, the quadrant of the sky lying toward the east, one of the four symbolic creatures among which the twenty-eight are shared out seven to each. In the later scheme that pairs every mansion with a creature, Di is assigned the Badger.

The twenty-eight mansions are among the oldest elements of Chinese sky-lore, attested well before the common era and used to track the nightly progress of the moon and to fix the calendar. The system is described here as that documented astronomical and calendrical tradition, from which its astrological uses later grew.

Di, the Root, is the third of the twenty-eight xiu and the third mansion of the eastern palace, the Azure Dragon. Its name is read as the root or base, sometimes the dragon's chest or foundation, identified with stars in Libra. In the later astrological tradition its animal totem is the Badger. As one of the twenty-eight lunar mansions it marks a segment of the sky along which the Moon's nightly position is tracked. These are the conventions of the Chinese astronomical and calendrical tradition, in which the twenty-eight xiu, grouped into the four palaces of the Azure Dragon, Black Tortoise, White Tiger, and Vermilion Bird, divide the heavens and underlie the almanac's assignment of auspicious and inauspicious days to the mansion the Moon occupies.

The Badger totem assigned to Di belongs to a set of twenty-eight animals that repeat in groups of four across the full cycle, each group of four sharing one of the seven classical Chinese "planets," the sun, moon and five visible planets, an arrangement also credited with giving East Asia its seven-day week, since the same seven bodies cycling through the mansions in fixed order supplied the sequence later adopted for the days themselves, still visible today in the Japanese weekday names for Sun, Moon, Fire, Water, Wood, Metal and Earth.