AST 1002 Lecture Notes - Lecture 7: W. M. Keck Observatory, Chromatic Aberration, Secondary Mirror
Document Summary
Telescopes tools of the trade - stars and other celestial objects are too far away to test directly. Astronomers passively collect radiation emitted from distant objs. Extremely faint objs make collection of radiation hard special instruments must measure brightness, spectra, and positions w/ high precision they use mirrored telescopes and observatories, not refractors. Modern astronomers are rarely at the eyepiece, are usually at terminal powers of a telescope - telescopes have 3 different powers. A secondary mirror may be used to deflect light to the side or thru a hole in the primary mirror. Multi-mirror instruments and thin mirrors are 2 modern approaches. Resolving power - pick out the details in an image interferometer telescope - resolution is increased for a larger telescope diameter simultaneously combines observations from 2+ widely spaced telescopes. Eso"s very big telescope captures close detail shot of star detecting light - The human eye: once used w/ a telescope to record observations/make sketches.
