How many times brighter than a magnitude +4.0 star is a magnitude +3.0 star?
A) 100 times brighter
B) twice as bright
C) a factor of 4/3, or 1.333 times, brighter
D) 2.512 times brighter

Question

Quizplus · Accepted Answer

The magnitude scale is logarithmic, with a difference of 5 magnitudes corresponding to a brightness factor of 100. Therefore, a difference of 1 magnitude corresponds to a brightness factor of the 5th root of 100, which is approximately 2.512.

How Many Times Brighter Than a Magnitude +4