Have you ever gone skeet shooting? If you haven’t it’s when you shoot clay pigeons with a shotgun. Anyway, the trick is to aim where the clay pigeon is going to be, not where it is now. If you aim directly at it, you will miss, but if you aim in front of it a little bit, the shot will intercept the clay pigeon.

Basically the same principle applies here. Aim for where the Star will be, not where it is. Account for both your and the stars relative speed, and calculate the coordinates to “aim” for. So actually it kinda would be a calculation done by the nav computer