Generally speaking,how does the surface temperature and luminosity of a protostar compare to the surface temperature and luminosity of the main-sequence star it becomes?
A)A main-sequence star is hotter and brighter than it was as a protostar.
B)A main-sequence star is cooler and dimmer than it was as a protostar.
C)A main-sequence star is cooler and brighter than it was as a protostar.
D)A main-sequence star is hotter and dimmer than it was as a protostar.

Question

Quizplus · Accepted Answer

As a protostar, the temperature and luminosity are high due to the gravitational energy released during the contraction process. However, as the protostar reaches equilibrium and becomes a main-sequence star, the temperature decreases and the luminosity stabilizes. This is because the energy generation within the star shifts from gravitational contraction to nuclear fusion, which produces a more steady and predictable output of energy. Therefore, a main-sequence star is hotter and dimmer than it was as a protostar.

Generally Speaking,how Does the Surface Temperature and Luminosity of a Protostar