What are the characteristics of Ursa major?

Ursa major is one of the Beidou constellations, located near Ursa minor and Leo, opposite Cassiopeia. The seven bright stars in Ursa Major are like spoons, which is what we often call the Big Dipper. 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. "

Ursa major has a famous binary star, which was called "Kaiyang Star" and "Auxiliary Star" in ancient China. They are often used to check people's eyesight. On a clear night, if the naked eye can see the auxiliary star next to Kaiyang Star, it can reach the standard value in vision examination.