ASTR 001 Lecture Notes - Lecture 12: Chromatic Aberration, Hans Lippershey, Diffraction
15 Jul 2020
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Document Summary
The telescope is the astronomer"s most important tool. Purpose: to gather light of all kinds. Two kinds of optical telescopes: reflecting and refracting. Suffers from (relatively) poor angular resolution, because the eye is small. Aperture: size of the objective lens (large aperture gathers more light) The objective lens is placed in the aperture. Focal length: distance between lens and the image (larger = larger image) The largest refracting telescope has a 1-meter aperture. Problems with refractors: need to be large to have a long focal length. Focal length is determined by the path the light takes reflecting off the mirrors. Bigger telescopes due to increased focal length in the same amount of physical space and no need for massive lenses. The largest telescopes in the world are reflectors. Optical and atmospheric limitations resolution=smallest details that can be separated. The longer the focal length, the better the separation of two objects or features.
