Rayleigh's critereon problem please check my work

[Dars]

Homework Statement

a telescope has a diameter of 8m. A double star 6000 light years away is viewed. what must be the min distance apart (in ly) of the two stars for their images to be distinguished if light of wavelength 500nm is used?

Homework Equations

theta = 1.22 (lamda/D)
D = 8m
lamda = 500e-9m

The Attempt at a Solution

theta = 7.6e-8 deg
theta/2 = 3.8e-8 deg (to find half distance between stars using right triangle)

sin(3.8e-8) (6000) = 3.979e-6

3.979e-6 * 2 = 7.959e-6m = distance between the two stars.

finally divide by c to get light years and i get 2.65e-14 ly... this is wrong though.. please help thanks

 

[Rick88]

Why did you divide by c?

If you have a distance in [m] and want to find the equivalent in [ly], you need to times the distance in [m] by the number of seconds in a year and by the value of c.R.