What is a standard candle?
A)an object for which we can easily measure its apparent brightness
B)an object for which we are likely to know its true luminosity
C)any star for which we know its exact apparent brightness
D)a class of objects that we know all have exactly the same luminosity
E)a unit of luminosity used by astronomers

Question

Quizplus · Accepted Answer

A standard candle refers to an astronomical object (such as a star) that has a known, standardized luminosity. By studying the apparent brightness of a standard candle, astronomers can then determine distances to other objects in the universe based on how bright they appear in comparison. Therefore, B is the best choice as it fits this definition of a standard candle.

What Is a Standard Candle