Question

A space-based telescope can achieve a diffraction-limited angular resolution of 0.14 for red light (wavelength 650 nm). What would the resolution of the instrument be in the ultraviolet, at 150nm ?

Answer 1

Answer:

I found  

0.032

radians.

Explanation:

I suppose here I am dealing with the Raileigh Criterion that tells us the minimum angular (in radians) separation between two object (emitting light of wavelength  

λ

) to strart to be discriminated (resolvable) by an aperture of diameter  

d

:

θ

R

=

1.22

λ

d

We have for the first wavelength:

0.14

=

1.22

650

×

10

−

9

d

so that  

d

=

5.664

×

10

−

6

m

For the second wavelengrt we have then a angular separation of:

θ

R

=

1.22

150

×

10

−

9

5.664

×

10

−

6

=

0.032

radians