I could be wrong but I think the difference in magnitude is around 3.8.Question
If the star lost 97% of it’s original brightness… what would be the equivalent in how many (star) magnitudes it dimmed ?
One magnitude is 2.512 x brighter or dimmer. So 2.512 to the power of 3.8 is 33 times brighter or dimmer. If a star is 33 times dimmer it is 1/33 the brightness or around 3%. Hope that's right!