An astronomer is observing a binary system with two stars of masses M₁ and M₂. She determines a, the semimajor axis (also the average distance between the stars) and P, the period of their motion. Using this information in Kepler's third law she can calculate A) M₁ or M₂ but not both. B) M₁/M₂. C) M₁ + M₂. D) both M₁ and M₂.

Question

Quizplus · Accepted Answer

Kepler's third law, when applied to a binary star system, allows for the calculation of the total mass of the system (M₁ + M₂) using the semimajor axis (a) and the orbital period (P). It does not directly provide the individual masses without additional information.

An Astronomer Is Observing a Binary System with Two Stars