What key factor must astronomers account for mathematically to derive a star's luminosity from its apparent brightness?

Answer

The known distance to the star.

Luminosity is the intrinsic power rating, whereas apparent brightness depends heavily on distance. Astronomers calculate luminosity by measuring the apparent brightness and then mathematically accounting for the star's known distance.

What key factor must astronomers account for mathematically to derive a star's luminosity from its apparent brightness?
temperaturepropertystarmassphysical