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-ONLY NEED PART C TO BE COMPLETED. MY ATTEMPT WAS RO TAKE d=2*theta(R)*L. Howeve

ID: 2250897 • Letter: #

Question



-ONLY NEED PART C TO BE COMPLETED. MY ATTEMPT WAS RO TAKE d=2*theta(R)*L. However the answer was wrong. The sample question had the following values:


8.71e-07

7.42e+07

0.0174

mm

What is the angular separation of two stars if their images are barely resolved by a refracting telescope with lens diameter 71 cm and its focal length is 15 m. Assume ? = 550 nm. Find the distance between these barely resolved stars if each of them is 11 light-years distant from Earth. For the image of a single star in this telescope, find the diameter of the first dark ring in the diffraction pattern, as measured on a photographic plate placed at the focal plane of the telescope lens. Assume that the structure of the image is associated entirely with diffraction at the lens aperture and not with lens "errors." What is the angular separation of two stars if their images are barely resolved by a refracting telescope with lens diameter 77 cm and its focal length is 10 m. Assume ? = 550 nm. Find the distance between these barely resolved stars if each of them is 9 light-years distant from Earth. For the image of a single star in this telescope, find the diameter of the first dark ring in the diffraction pattern, as measured on a photographic plate placed at the focal plane of the telescope lens. Assume that the structure of the image is associated entirely with diffraction at the lens aperture and not with lens "errors."

Explanation / Answer

What is the angular separation of two stars if their images are barely resolved by a refracting telescope with lens diameter 71 cm and its focal length is 15 m. Assume ? = 550 nm.

solution :
angular separation, theta = (1.22)* lambda / diameter = (1.22)*(550*10^-9 m) / (0.71 m) = 9.451*e-7 rad (== 0.195* pi / (3600 * 180))



Find the distance between these barely resolved stars if each of them is 11 light-years distant from Earth

solution;

distance between two stars , D = L * theta = (11 ly) *(9.46*10^12 km/ly)*(0.195* pi) / (3600 * 180) = 9.83*10^7 km



For the image of a single star in this telescope, find the diameter of the first dark ring in the diffraction pattern, as measured on a photographic plate placed at the focal plane of the telescope lens. Assume that the structure of the image is associated entirely with diffraction at the lens aperture and not with lens "errors."

solution :

d = 2*theta*l = 2*0.195* pi * 15m / (3600 * 180) = 2.836*10^-5 m = 0.0284 mm.