It is almost the same
You'll hace to use DynamicAligment, and select only the core of the comet (only 1 sample). This way all images will be shifted (x and y coordinates) to match the comet. Of course, if you have rotations, this is not the best way to go. You may probably do a automatic registration with the stars, to correct rotation/distortions and then a shift with DA and the comet's core.
Now, it you want to have the comet AND the stars without drift... this is more difficult, but can be done
