Question

comparing absolute and apparent brightness
which statement describes absolute and apparent brightness?
○ absolute brightness and apparent brightness are identical ways to describe the brightness of a star.
○ absolute brightness and apparent brightness change with the distance from the star to the observer
○ absolute brightness depends on the distance from the star to the observer, whereas apparent brightness is always the same.
○ absolute brightness is the actual amount of light produced by the star, whereas apparent brightness changes with distance from the observer.

Explanation:

• Option 1: Absolute and apparent brightness differ, so they aren’t identical. Eliminate.
• Option 2: Absolute brightness (actual light) doesn’t change with distance; apparent does. Eliminate.
• Option 3: Absolute brightness is independent of distance (it’s the star’s actual light output), so this is reversed. Eliminate.
• Option 4: Absolute brightness is the star’s actual light production. Apparent brightness depends on the observer’s distance (since light spreads with distance, so the observer sees less as distance increases). This matches the definitions.

Answer:

Absolute brightness is the actual amount of light produced by the star, whereas apparent brightness changes with distance from the observer.