All of the following are useful in determining the masses of stars in a binary system EXCEPT
A) the period of the orbits of the two stars.
B) the average separation between the two stars.
C) the luminosities of the two stars.
D) the velocities of the two stars.

Question

Quizplus · Accepted Answer

The luminosities of the two stars are not directly related to their masses, so they cannot be used to determine the masses of stars in a binary system. The period of the orbits, the average separation, and the velocities of the two stars are all useful in determining their masses through the application of Kepler's laws and Newton's laws of motion.

All of the Following Are Useful in Determining the Masses