1. The problem statement, all variables and given/known data What is the minimum angular separation an eye could resolve when viewing two stars, considering only diffraction effects? 2. Relevant equations θ=(1.22*λ)/D 3. The attempt at a solution I tried estimating with λ=550 nm and D=5.0 mm (pupil diameter) which appeared in another problem about viewing stars and got 1.34e-4 rad, but this was incorrect. Our book states the best eye resolution is around 5e-4 rad so I tried that as well, but it wasn't correct either. This problem must want something more concrete than an estimation but I'm not sure where to go with it.