Assuming that we can measure the apparent brightness of a star, what does the inverse square law for light allow us to do?
A) Determine both the star's distance and luminosity from its apparent brightness.
B) Determine the distance to the star from its apparent brightness.
C) Calculate the star's luminosity if we know its distance, or calculate its distance if we know its luminosity.
D) Calculate the star's surface temperature if we know either its luminosity or its distance.
Answer: C