17.48: In the binary star sy
pb fafh9xp p43z ;r)3xstem shown, the two stars follow circular orbits about the system’s center of mass. The stars are separated by a distance D that is large compared to their size and a
fap xh34bp;) z9 r3xfpre subject only to their mutual gravitational attraction. The orbital period of the star of mass M is T. Which one of the following choices represents the total mass of the binary star system?