A star's luminosity is the

Question

Quizplus · Accepted Answer

Luminosity is defined as the total amount of energy radiated per unit time. Therefore, choice A - total amount of energy that the star radiates each second - is the correct answer. Choice B is incorrect because it refers to the total amount of energy radiated over the star's entire lifetime, not per unit time. Choice C is incorrect because it refers to the star's lifetime, which is not directly related to the amount of energy it radiates. Choice D is incorrect because apparent brightness depends not only on luminosity but also on distance. Choice E is incorrect because surface temperature is not the same as luminosity; a cool, low-luminosity star can have the same temperature as a hot, high-luminosity star.

A Star's Luminosity Is the