Assume that two stars are in circular orbits about a mutual center of

mass and are separated by a distance a. Assume also that the angle of

inclination i and their stellar radii are r1 and r2.

(a) Find an expression for the smallest angle of inclination that will pro-

duce an eclipse. Hint: Refer to Figure 7. 8 of your text.

(b) If a = 2 AU, r1 = 10 R⊙, and r2 = 1 R⊙, what minimum value of i

will result in an eclipse?