Consider a double star system under the influence of the gravitational force between the stars. Star 1 has mass m1 = 1.72 × 1031 kg and Star 2 has mass m2 = 1.60 × 1031 kg. Assume that each star undergoes uniform circular motion about the center of mass of the system (cm). In the figure below r1 is the distance between Star 1 and cm, and r2 is the distance between Star 2 and cm.
If the stars are always a fixed distance s=r1+r2 = 3.05 × 1018 m apart, what is the period of the orbit (in s)?