What is Ursa major?

In ancient China, the seven bright stars in Ursa Major were considered to be in the shape of a spoon, which is what we often call the Big Dipper. You see, the three stars η, ζ and ε are the handle of the spoon, and the four stars α, β, γ and δ make up the spoon body. In fact, when looking at the constellation Ursa major, the shape of the spoon is easier to see than the image of the bear. This big spoon is in the sky all year round, and the direction of the handle changes in different seasons, and one season happens to be one direction. In the words of the ancients, it is: "bucket handle refers to the east, and the world is spring; Bucket handle guide, the world is summer; Bucket handle refers to the west, and the world is autumn; Bucket handle refers to the north, and it is winter in the world. " There was no calendar in ancient times, so people used this method to calculate the four seasons. Of course, due to the rotation of the earth, this phenomenon must be seen after eight o'clock in the evening.

Ursa major is undoubtedly the most striking and important constellation in the northern sky, and astronomers all over the world attach great importance to it. We often say that "the sky is full of stars", which shows that China people simply regard Beidou as a synonym for the stars in the sky. The ancient astronomers in China specially named each star of the Big Dipper, especially called the four stars of the bucket α, β, γ and δ "Kui". Wei Xiao is the legendary Wenquxing. In ancient times, it was the god in charge of examinations. In the imperial examination era, it is the only way for children from poor families to get ahead. Every big exam, I don't know how many people look up to Beidou and pray silently!

The second star on the spoon handle is Zeta Star, which was called Kaiyang Star in ancient China. If you look carefully, you will find a dark star near it. This dark star is called Ursa Major 80. The ancients saw that it was always close to Kaiyang Star, just like the patron saint of Kaiyang Star, so it was called Fu. Kaiyang star and auxiliary star form a pair of binary stars.

At different latitudes of the earth, the constellations you can see are different. The constellation Ursa major can be seen all year round in areas above 40 north latitude, that is, to the north of Beijing and Greece. However, in spring, Ursa major hangs high in the northern sky, which is the best time to watch it in four seasons.