AST 111 Chapter Notes - Chapter 1: Galactic Halo, Proper Motion, Emission Spectrum
6 Jun 2020
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Document Summary
Refers to the faint band of light crossing the sky that can be seen on a dark night. When galileo used his telescope he found that the band was composed of many star. Further studies revealed that the milky way was a vast system containing billions of stars as well as clouds of dust and gas. We now know that the milky way is just one of many billions of similar systems these are referred to as galaxies. So our own galaxy is the milky way galaxy. We are inside so we can look at it from outside. Contains a lot of dust that obscures the view at visible wavelengths. Other wavelengths are needed to get a complete picture. A disk: a flat disk of stars about 100,000 light years across and 1000 light years thick. About 200 globular clusters distributed in the halo. Stars in the galaxy are in orbit around the centre of mass of the galaxy.
