I used a telescope to look at the stars, and they kept moving. What is this?

There are two main reasons:

1. If you shoot handheld, there will be jitter in the photos. This is the main reason.

2. Due to the detachment caused by the rotation of the earth, the stars in the sky rotate around the North Star on the celestial sphere. It is difficult to identify their movement when observing with the naked eye, but after a while we will find that the positions of the stars have indeed changed. . Star track photography in astrophotography is based on this principle.

The crookedness of the stars in your photos is mainly due to the movement of the lens. You can try a mobile phone holder to fix the mobile phone or camera for shooting.