What is Zhonggong?

Ziweiyuan is the middle wall of three yuan, living in the center of the northern sky, so it is also called Zhonggong, or Ziweiyong. Wei Zi Palace means Imperial Palace, and most stars are named after official names. It is in the extreme center of the north, with 15 stars in the east and 15 stars in the west. The two bows were joined together and surrounded by a wall. According to the observation records of the whole Ziweiyuan during the reign of Emperor You of Song Dynasty, there are 37 constellations, including 2 satellite seats, positive star 163, and additional star 18 1. Its sky area is roughly equivalent to the international constellations of Bear, Bear, Dragon, Hound, Mu Fu, Unbounded Constellation, Wang Xianxing, Hou Xian Constellation, Yingxian Constellation and Lubao Constellation.