The star Alphard has an apparent magnitude of 2.0, and the star Megrez has an apparent magnitude of 3.3. The only thing that can be said with certainty about Alphard is that it is _____ than Megrez.
A) brighter, as seen in Earth's sky
B) more luminous
C) fainter, as seen in Earth's sky
D) closer to Earth

Question

Quizplus · Accepted Answer

The apparent magnitude scale is a measure of the brightness of stars as seen from Earth, where lower numbers indicate brighter objects. Since Alphard has a lower apparent magnitude (2.0) than Megrez (3.3), it is brighter as seen from Earth's sky. This measure does not directly inform us about the star's luminosity (intrinsic brightness) or distance without additional information.

The Star Alphard Has an Apparent Magnitude of 2