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. -- Table of Contents Stars Can Be Categorized Using Their Spectra 1:32 Spectra With Distance Can Identify Luminosity, Size, and Temperature 5:20 The HR Diagram Plots Luminosity vs Temperature 6:33 Most Stars Fall Along the Main Sequence 7:16 -- PBS Digital Studios: http://youtube.com/pbsdigitalstudios Follow Phil on Twitter: https://twitter.com/badastronomer Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com Support CrashCourse on Patreon: http://www.patreon.com/crashcourse -- PHOTOS/VIDEOS Stars http://www.nasa.gov/images/content/703724main_potw1244a.jpg [credit: ESA/Hubble & NASA] Spitzer Spectrum http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA03242 [credit: NASA/JPL-Caltech/Leiden/SRON] Sun spectrum https://www.noao.edu/image_gallery/html/im0600.html [credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF] Annie Jump Cannon https://en.wikipedia.org/wiki/Annie_Jump_Cannon#/media/File:Annie_Jump_Cannon_1922_Portrait.jpg [credit: New York World-Telegram and the Sun Newspaper] Cecilia Payne-Gaposchkin https://en.wikipedia.org/wiki/Cecilia_Payne-Gaposchkin#/media/File:Cecilia_Helena_Payne_Gaposchkin_(1900-1979)_(3).jpg [credit: Smithsonian Institution] OBAFGKM https://www.noao.edu/image_gallery/html/im0649.html [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/multimedia/imagegallery/image_feature_468.html [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_spectrum_with_visible_spectrum_background_(en).png [credit: Danmichaelo, Wikimedia Commons] Blue sky http://www.pexels.com/photo/sky-sunny-clouds-cloudy-3768/ [credit: Skitter Photo] Hawaii sunset photo [credit: Phil Plait] Hertzsprung-Russell Diagram https://commons.wikimedia.org/wiki/File:ESO_-_Hertzsprung-Russell_Diagram_(by).jpg [credit: ESO]