Astronomical objects that visibly change in human timescales are pretty rare. A naked-eye visible supernova remnant was one of the first clues that challenged the idea that the heavens were static, permanently set by God.
One of my favorite examples of astronomical timelapse is the motion of objects around SagA*. That I think might be the first example I saw. I'm not sure if they set out to make multiple observations specifically to map this motion or if it was something saw they could do from existing data. S