What is the minimum lens size (in meters) that will permit just resolving 2 stars 1.1 second apart using light of 510nm?

Answer 1

Limiting resolution (in radians)
= 1.22 (wavelength)/(diameter)

1.1 arc second = [1.1 sec/(3600 sec/deg*)]*1 rad/57.3 deg = 5.33*10^-6 rad

5.33*10^-6 = 1.22*510*10^-9/D

Solve for diameter D

Answer 2

Is D~11.7*10^-2

Answer 3

i solved D~11.7*10^-2, but the answer key is .0956