The concept of constellation?

The ancients observed the starry sky. There were too many stars. It's convenient to communicate with others, and remember whether they are in different regions.

Therefore, the sky is divided into 88 regions, and each region is arranged according to the stars. Imagine something, a constellation. Among them, there are 12 constellations on the ecliptic (the circle through which the sun passes), which is the zodiac. Among the saints, there are golden warriors. The constellations in the northern celestial sphere are all bronze among saints, and the constellations in the southern celestial sphere are all silver.

In ancient China, there was a similar division, and in ancient China, the sky was divided into three walls and twenty-eight lodges based on the same consideration.

For the distribution of 28 hotels in Sanyuan, you can refer to the astronomical volume of Encyclopedia of China, and the song of the sky also records the division of 28 hotels in Sanyuan.