Chapter 19, Problem 44A

To determine

To Complete:The problem so that it can be solved using Rayleigh criterion for the aperture of telescope as 8 m.

Explanation of Solution

Introduction:

The minimum resolvable angle for telescope is given as,

  $\theta =1.22\frac{\lambda }{D}$

Here, $\lambda$ is wavelength and D is the aperture of the telescope.

The question could be, “A telescope currently being designed is to have an aperture that is 8 m in diameter. It avoids effect of degrading on its resolution due to atmospheric distortion. Take average wavelength of 550 nm. For two just-resolvable point light sources, what is the angle between them?”

So,

  $\begin{array}{l}\theta =1.22\times \frac{550\times {10}^{-9}}{8}\\ =8.39\times {10}^{-8}\text{rad}\end{array}$