According to the Stefan-Boltzmann law, how does the luminosity of a medium mass or massive main sequence star change as its outer layers expand and cool off, as it becomes a giant or supergiant?
A. It becomes dimmer.
B. It remains the same.
C. It becomes brighter.
D. (Any of the above (A)-(C) choices, depending on how old the star is.)
Answer:B
According to the Stefan-Boltzmann law, how does the luminosity of a medium mass or massive main sequence star change as its outer layers expand and cool off, as it becomes a giant or supergiant?
A. It becomes dimmer. B. It remains the same. C. It becomes brighter. D. (Any of the above (A)-(C) choices, depending on how old the star is.)