11.12.2007 - astronomy notes

11.12.2007 - astronomy notes - MS Giant Gas dense gas...

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11.12.2007 – Astronomy Test on Friday: chapter on telescopes through stellar evolution Hertzprung-Russel Diagrams: Luminosity is proportional to R^2 T^4 Main sequence: the vast majority of hydrogen burning stars fall along this line All stars are born on the main sequence. Parallax can be used to get distance, brightness 90% of stars are on the main sequence. 1% are red giants. 9% are white dwarfs. White dwarfs are the remnants of larger stars, carbon, nitrogen. Spectroscopic parallax Main sequence only Brightness = Luminosity / 4pi distance^2 Only 25% accurate Luminosity class: spectral lines look different for different classes (density of gases).
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Unformatted text preview: MS Giant Gas dense gas sparse Doppler broadening Wide absorption lines narrow lines Cosmic distance ladder Binary stars-Visual binary o Measure period by watching it go around o Semi major axis (a) = + ar2 at2 Newtons form of keplers third law gives you the sum of the masses Radius of star is proportional to its mass Luminosity is proportional to mass ^4 Stellar lifetime Roughly = mass / luminosity (how much fuel you have over burn rate) M ^ -3 Mass Lifetime 10 10^7 1 10^10 0.1 10^13...
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This note was uploaded on 09/24/2009 for the course ASTR 101 taught by Professor Christiansen during the Fall '08 term at UNC.

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