Chapter 35, Problem 9CQ

To determine

Which of the following actions would improve the resolution if an astronomer is trying to observe two distant stars? The stars are marginally resolved when she looks at them through a filter that passes green light with a wavelength near 550 nm. Assume that the resolution is not limited by the atmosphere.

A) Changing the filter to a different wavelength. If so, should she use a shorter or a longer wavelength?

B) Using a telescope with an objective lens of the same diameter but a different focal length. If so, should she select a shorter or a longer focal length?

C) Using a telescope with an objective lens of the same focal length but a different diameter. If so, should she select a larger or a smaller diameter?

D) Using an eyepiece with a different magnification. If so, should she select an eyepiece with more or less magnification?