Rayleigh's critereon problem please check my work

AI Thread Summary
The discussion revolves around calculating the minimum distance between two stars for a telescope with an 8m diameter to distinguish their images at a distance of 6000 light years, using light with a wavelength of 500nm. The initial calculation yielded a distance of 2.65e-14 light years, which was identified as incorrect. Participants pointed out that to convert meters to light years, the correct approach involves multiplying the distance in meters by the number of seconds in a year and the speed of light. The error stemmed from incorrectly dividing by the speed of light instead of using the appropriate conversion factors. Clarification on the conversion process was sought to resolve the misunderstanding.
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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
 
Physics news on Phys.org
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.
 

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