PHYS 1010 Chapter Notes - Chapter 14: Spiral Galaxy, Parsec, Red
23 Apr 2016
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Document Summary
From earth we see few stars when looking out of galaxy (red arrows), many when looking in (blue and white arrows) Milky way is how our galaxy appears in the night sky. One of the first attempts to measure the milky way was done by herschel using stars. Problem was that he was looking at only visible stars. Unfortunately, he was not aware that most of the galaxy, particularly the center, is blocked from view by vast clouds of gas and dust. We have already encountered variable stars nova and binary eclipses. There are other stars whose luminosity varies in a regular way, but this is an intrinsic trait of the star itself. Two types of pulsating variable stars that have been very important: rr lyrae stars and. The upper plot is an rr lyrae star. All such stars have essentially the same luminosity curve, with periods from 0. 5 to 1 day.
