Remember Kepler's third law, which relates the period of revolution to the average distance to a planet. How do we modify that law to use with binary stars?

Question

Remember Kepler's third law, which relates the period of revolution to the average distance to a planet.   How do we modify that law to use with binary stars?

Quizplus · Accepted Answer

In the case of binary stars, we need to use the combined mass of both stars to modify Kepler's third law. The equation becomes T^2 = (4π^2/G(M1+M2)) * a^3, where T is the period of revolution, a is the average distance between the two stars, G is the gravitational constant, and M1 and M2 are the masses of the two stars.

Remember Kepler's Third Law, Which Relates the Period of Revolution