Star E is the same temperature as star F but is four times as luminous.Which star is bigger?
A) Star E is twice as big as star F.
B) Star E is four times as big as star F.
C) Star F is twice as big as star E.
D) Star F is four times as big as star E.

Question

Quizplus · Accepted Answer

The luminosity of a star is proportional to its surface area and the fourth power of its temperature. Since both stars have the same temperature, the difference in luminosity is due to the difference in size. Star E is four times as luminous as star F, so it must have twice the radius, making it twice as big in terms of surface area.

Star E Is the Same Temperature as Star F but Is