The 28 Lunar Mansions (二十八宿)

The 28 Lunar Mansions (二十八宿)

The 28 Lunar Mansions (二十八宿, Er Shi Ba Xiu) form the primary coordinate system of QZSY and one of the oldest astronomical frameworks in Chinese civilisation. Unlike the Western zodiac's twelve equal 30-degree divisions, the 28 mansions divide the celestial equator into unequal segments based on the positions of determinative stars (距星). Each mansion's angular span ranges from as little as 2 degrees to over 33 degrees, reflecting the actual distribution of bright reference stars around the sky.

The Four Symbols (四象)

The 28 mansions are grouped into four sets of seven, each governed by one of the Four Symbols (四象) — mythological creatures that guard the four cardinal directions:

Complete Mansion Reference

Comparison with Vedic Nakshatras

The 28 Chinese Lunar Mansions share a common ancestor with the 27 Vedic Nakshatras (नक्षत्र, நட்சத்திரம்). Both systems divide the sky into mansion-like segments based on the Moon's nightly progress (the Moon moves approximately one mansion per day). The Indian system uses 27 equal divisions of 13°20' each, while the Chinese system uses 28 unequal divisions based on actual star positions. Scholars debate whether the two systems developed independently or share a common Central Asian or Mesopotamian origin. The Chinese addition of a 28th mansion may reflect the desire to align with the four weeks of a lunar month (7 x 4 = 28).