Two stars orbit each other in a binary system. Each star by itself has an apparent magnitude of 4.0. What is the apparent magnitude of the two seen together as a single object?

Question

Quizplus · Accepted Answer

The apparent magnitudes of two stars combined can be calculated using the formula for combining magnitudes: m = -2.5 * log10(10^(-m1/2.5) + 10^(-m2/2.5)). For two stars each with a magnitude of 4.0, the combined magnitude is approximately 3.25.

Two Stars Orbit Each Other in a Binary System