Kang, the Neck of the Azure Dragon

Kang, the Neck, is the second of the twenty-eight xiu and the second mansion of the eastern palace, the Azure Dragon of spring. As the Neck it marks the throat of the celestial dragon, identified with stars in Virgo. In the later astrological tradition its animal totem is the Dragon. Each of the twenty-eight lunar mansions is defined by a determinative star from which its position is measured, and together they divide the band of sky the Moon and sun travel. These are the conventions of the Chinese astronomical and calendrical tradition, distinct from the Indian and Arabic lunar-mansion systems though serving the same function of tracking the Moon: the twenty-eight xiu order the sky into four palaces of seven, each palace a great symbolic animal spanning one quarter of the heavens.

The determinative-star method used to fix Kang's boundary, measuring along the celestial equator from a single named reference star rather than dividing the sky into equal arcs, is the same principle underlying all twenty-eight xiu and is why the mansions are so unequal in width, some spanning only a degree or two and others many times that; the Chinese system shares this unevenness with the Arabic manazil, whose boundaries were likewise fixed from named stars, in contrast to the more strictly equal thirteen-degree-twenty-minute divisions of the classical Indian nakshatra scheme.