Question
A binary star system has been observed to have an orbital semi-major axis of 2.5 AU and an orbital period of 2 years. Assume that the system is viewed edge-on so you are seeing the full range of motion. What is the total mass of the binary star in solar masses?
Answers
oobleck
just apply Kepler's 3rd law
M = 4π^2 a^3 / GT^2
M = 4π^2 a^3 / GT^2