Is the measure of how bright a star would be if it were located at a standard distance from Earth.

The correct answer is "Absolute Magnitude".

Explanation:

Absolute magnitude is a measure of luminosity applied to celestial objects such as stars. In contrast to other measures such as apparent magnitude, absolute magnitude uses a standard distance from Earth as scale, particularly, the distance of exactly 10 parsecs (32.6 light-years). The symbol of absolute magnitude is "M", and in the case of stars, it usually has a measure from - 10 to + 17.