Two stars in our sky have the same apparent brightness.If neither of them is hidden behind gas or dust clouds,then we know that they:
A) must be at the same distance from us.
B) may be at different distances, in which case the nearer one must have the greater luminosity.
C) may be at different distances, in which case the farther one must have the greater luminosity.
D) must have the same temperature.

Question

Quizplus · Accepted Answer

If two stars have the same apparent brightness but are at different distances, the farther star must have greater luminosity to appear as bright as the nearer one.

Two Stars in Our Sky Have the Same Apparent Brightness