Two stars are 2.1 Ã- 1011 m apart and are equally distant from the earth. A telescope has an objective lens with a diameter of1.39 m and just detects these stars as separate objects. Assume that light of wavelength 540 nm is being observed. Also, assume that diffraction effects, rather than atmospheric turbulence, limit the resolving power of the telescope. Find the maximum distance that these stars could be from the earth.