What is Ursa minor?

The position of Ursa minor A: 9h18m ~ 21h0m+68 ~+86 is in the northernmost part of the sky, in which A is the Polaris, facing the North Pole of the earth, and was even regarded as the symbol of emperors in ancient China. The seven stars in Ursa minor also form a "small spoon" like the Big Dipper, except that A and β are second-class stars and γ is third-class, and all the others are smaller stars darker than 4. The big dipper shaped like Ursa major. But smaller and darker. Polaris is also a binary star, but its companion star is very dark. In addition, it should be said that Polaris is not located in the exact north pole of the celestial sphere, but it is 1 away from the north pole of the celestial sphere. But in this range, there is no bright star closer to the north pole of the celestial sphere than Ursa minor A, so it is regarded as the north star.