Which term refers to the brightness a star would have if it were at a standard distance from Earth?

• A. Apparent magnitude
• B. Absolute brightness
• C. Light year
• D. Astronomical Unit (AU)

Answer: (B)

The concept is intrinsic brightness and how we quantify it using a standard distance. Absolute magnitude is the measure of how bright a star would appear if it were placed at a fixed distance of 10 parsecs from Earth. This standard distance lets us compare true luminosities without distance getting in the way. Apparent magnitude, by contrast, tells us how bright the star looks from Earth, which depends on how far away it is. A light year and an astronomical unit are both units of distance, not brightness. So the description matches absolute magnitude, the term used for intrinsic brightness at a standard distance from Earth.