You observe a red star and a blue star and are able to determine that they are the same size.Which star has a higher surface temperature, and which star is more luminous?
A) The red star has a higher surface temperature and is more luminous.
B) The red star has a higher surface temperature, and the blue star is more luminous.
C) The blue star has a higher surface temperature and is more luminous.
D) The blue star has a higher surface temperature, and the red star is more luminous.
E) They have the same luminosities and temperatures.

Question

Quizplus · Accepted Answer

The blue star has a higher surface temperature because blue stars are hotter than red stars. Since they are the same size, the blue star is also more luminous.

You Observe a Red Star and a Blue Star and Are