If all effects caused by Earth's atmospheric variations (seeing) could be removed from the visible image of a star on one of the 10-m diameter Keck telescopes on Hawaii, what would be the angular resolution achievable by this telescope in arcseconds for light of wavelength 500 nm? (1 nm = 10^-9 m)

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Quizplus · Accepted Answer

The angular resolution of a telescope is given by the formula $R\approx\frac{\lambda}{D}$, where $\lambda$ is the wavelength of the light and $D$ is the diameter of the telescope. Substituting $\lambda=500$ nm and $D=10$ m, we get $R\approx0.0125$ arcsec. Removing the effects caused by Earth's atmospheric variations would improve the angular resolution, so the achievable angular resolution would be equal to or better than $0.0125$ arcsec. The closest option is D, which is the correct answer.

If All Effects Caused by Earth's Atmospheric Variations (Seeing) Could