Question

which characteristic is used to measure the amount of light radiated by a star?
○ size
○ color
○ luminosity
○ temperature

Explanation:

• Size of a star relates to its physical dimensions, not the light it radiates.
• Color of a star is related to its temperature and spectral class, not the amount of light radiated.
• Luminosity is defined as the total amount of light energy a star emits per unit time, so it measures the amount of light radiated by a star.
• Temperature of a star affects its color and energy production mechanism, not directly the amount of light radiated (though related, it's not the measure of light radiated).

Answer:

C. luminosity