How is the month of the constellation determined?

The friend upstairs extracted a large piece of information, which also has some merits. The landlord may wish to have a look.

Admittedly, according to the landlord's point of view, there is really no way to see Virgo directly in September. However, the direct observation of the position of celestial bodies with the naked eye is only the performance of the initial stage of astronomy. When human civilization enters a relatively high stage, the accuracy and integrity of astronomical observation will be greatly improved.

As far as the landlord is concerned, we have progressed from observing the single position of the celestial body to deducing the orbit of the celestial body. There were twelve constellations near the ecliptic in ancient Greece, and twelve ecliptic stars were established in China in the Western Zhou Dynasty. In other words, the concept of the ecliptic, whether in the east or in the west, has been put forward in the era of classical civilization. In other words, humans have begun to systematically observe the position of the sun, so as to calculate its orbit more accurately.

How to do it specifically? The principle is also very simple. What is the longitude of the sun? It is not easy to observe during the day ... simple, at night, the relative longitude of the celestial body at midnight is the angle of the sun. What about the latitude of the sun? Well, it's a little troublesome because it keeps changing ... but it doesn't matter. I'll test again in half a year. With the determination of each point, the orbit of the sun can be roughly deduced.

Of course, the principle is simple, and the actual operation method will certainly be much more complicated. The breakthrough progress in the Middle Ages was very limited, but it should also be affirmed that the astronomical observation accuracy in China, the West and Arab countries was one or two orders of magnitude higher than that in the classical era.

Finally, knowing the orbit of the sun and calculating the position of the sun at a certain moment is a job that primary school students can also complete. By the way, the other six of the seven obsidians are more complicated than the movement of the sun, but the specific methods are similar. Draw the trajectory one by one, then find the law and push the trajectory, so as to make a fairly accurate forecast.