A ground–based optical telescope has a circular objective of diameter 0.20m. The telescope is used with light of wavelength 550nm to study a pair of stars that are at the same distance from Earth.
(i) Calculate the smallest angular separation (in arc–seconds) that can just be distinguished by this telescope.
(ii) The two stars are 4.0×1016m away. Using your result of part (i), find the minimum linear distance that must separate the two stars so that they appear as just resolved to the observer.