Stars: Crash Course Astronomy #26

Today Phil’s explaining the stars and how they can be categorized using their spectra. Together with their distance, this provides a wealth of information about them including their luminosity, size, and temperature. The HR diagram plots stars’ luminosity versus temperature and most stars fall along the main sequence, where they live most of their lives.


Check out the Crash Course Astronomy solar system poster here: http://store.dftba.com/product....s/crashcourse-astron

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Chapters:
Introduction: Stars 00:00
Stellar Spectra 1:07
Star Classifications 3:03
Why Are There No Green Stars? 4:00
Luminosity Depends on Size and Temperature 5:27
The HR Diagram 6:33
Main Sequence Stars 7:27
Other Stars on the HR Diagram 8:17
Review 9:50
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PHOTOS/VIDEOS
Stars http://www.nasa.gov/images/con....tent/703724main_potw [credit: ESA/Hubble & NASA]
Spitzer Spectrum http://www.jpl.nasa.gov/spacei....mages/details.php?id [credit: NASA/JPL-Caltech/Leiden/SRON]
Sun spectrum https://www.noao.edu/image_gal....lery/html/im0600.htm [credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF]
Annie Jump Cannon https://en.wikipedia.org/wiki/....Annie_Jump_Cannon#/m [credit: New York World-Telegram and the Sun Newspaper]
Cecilia Payne-Gaposchkin https://en.wikipedia.org/wiki/....Cecilia_Payne-Gaposc [credit: Smithsonian Institution]
OBAFGKM https://www.noao.edu/image_gal....lery/html/im0649.htm [credit: NOAO/AURA/NSF]
Betelgeuse http://www.eso.org/public/usa/images/eso0927e/ [credit: ESO/Digitized Sky Survey 2. Acknowledgment: Davide De Martin]
Sirius https://www.nasa.gov/multimedi....a/imagegallery/image [credit: NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester)]
Solar AM0 spectrum with visible spectrum background https://commons.wikimedia.org/....wiki/File:Solar_AM0_ [credit: Danmichaelo, Wikimedia Commons]
Blue sky http://www.pexels.com/photo/sk....y-sunny-clouds-cloud [credit: Skitter Photo]
Hawaii sunset photo [credit: Phil Plait]
Hertzsprung-Russell Diagram https://commons.wikimedia.org/....wiki/File:ESO_-_Hert [credit: ESO]