Using the Bessel equation estimate
theta= 1.22 wavlength/diameter
but for small angles, theta=separation/distance
so
distance=separation*diameter/ 1.22*wavelength
which is about= 4.4E11*1.03/1.22*550E-9
=about 4E18/6= .7E18m
check my math, you do it more accurately.
Two stars are 4.40 1011 m apart and are equally distant from the earth. A telescope has an objective lens with a diameter of 1.03 m and just detects these stars as separate objects. Assume that light of wavelength 550 nm is being observed. Also assume that diffraction effects, rather than atmospheric turbulence, limit the resolving power of the telescope. Find the maximum distance that these stars could be from the earth.
1 answer