How to Calculate How Bright a Star Is in Reality

There's a lot of work going on to try to like nail that down more precisely. And then there's another step in the distance ladder because cephids are great and they're in distant galaxies but they're not that bright so for like really far away galaxies you can't see them. And then about 20 years ago people found another element to add to the distance ladder which were type 1a supernova. So now we have again just a handful of galaxies that have both cephids and type 1aSupernovas where we can cross calibrate and add like another plank to our distance ladder.