Two newly discovered planets follow circular orbits around a star in a distant part of the galaxy. The orbital speeds of the planets are determined to be 41.7 km/s and 55.5 km/s. The slower planet's orbital period is 8.04 years. (a) What is the mass of the star? (b) What is the orbital period of the faster planet, in years?
The Attempt at a Solution
I assume that the radius of the slower moving planet must be found first. Also, as for finding the period, does that same r need to be found, or is this going to be a very elaborate "plugging in the variables" type of equation?