[SOLVED] Binary star system and Apparent magnatudes I was asked this questing in my tetbook and can't figure out how to do it. Suppose there is a binary system made up of two identical stars, each with an apparent magnitude of +4.1. However, from our 40 cm telescope they appear as one star, i.e., they are unresolved. What would be the apparent magnitude of this ``star?" I figure that the two stars apparent magnatudes must add together to get this magnatude somehow but I am not quite sure how, because 100 magnitude 6 stars = a magnitude 1 star. is there some simple formula to figure this out.