The luminosity of a star is
A) its brightness as seen by people on Earth.
B) its brightness if it were at a distance of 10 pc (32.6 ly) from Earth.
C) its total energy output into all space.
D) another name for its color or surface temperature.

Question

Quizplus · Accepted Answer

Luminosity is defined as the total energy output of a star into all space, not just how bright it appears from Earth or at a specific distance.

The Luminosity of a Star Is