What are the explanations for the appearance and entrance?

Phase advance is the state that two stars are entering this phase, and phase out is the state that two stars have formed this position and are running out of this position. It seems so. Generally speaking, the input stage has a greater impact because of its long duration.

On the astrolabe, the angle formed between the planets is the phase. Different angles of formation of different planets will also lead to different trends of fortune, good and bad. In fact, some concepts on the astrolabe are easy to understand, and some can be known according to their meanings.

The origin of the constellation:

Mesopotamian astrologers divided the starry sky into several regions for the convenience of studying and observing many stars in the sky, and each region was a constellation. It's hard to say clearly when humans began to have the concept of constellation. This astronomical knowledge was known long before there was a historical record. The name of the constellation probably comes from the sailors who sailed early.

The origin of constellations may be completely different between civilizations in different regions, but with the expansion and mutual influence of civilizations, the culture of constellations also includes the process of integration.