ASTRON 1F03 Lecture Notes - Lecture 21: Hubble Deep Field, Emission Nebula, Parsec
18 Dec 2015
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Document Summary
Prior to the great debate of 1920, it was unclear if the universe consisted of: the disk-like collections of stars around the sun, now called the milky way. Or: there were many galaxies distributed through space. Great debate of 1920: the discovering of galaxies. The argument was whether the fuzzy nebulae in the sky were: all local objects in our galaxy (e. g. emission nebula, young star clusters, sometimes huge collections of stars at great distances. A galaxy is a large collection of stars and gas. A galaxy like the milky way contains some 10 billion stars. There are hundreds of billions of galaxies in the universe. This is the hubble deep field a tiny partch of sky. Just a handful of stars in this image. A very long, deep exposure with hst. Cosmology is the study of the structure and evolution of the whole universe. Historically, the term cosmology could refer to creation myths or other explanations for the universe.
