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Astronomy 100. Are All Stars the Same?. Answer Now: Why does the Sun shine? Are all stars the same as our Sun? (How or how not?) Goal: Be able to tell me how stars are born Know what stars are made of Know how stars shine (if we have time) Know how stars die
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Astronomy 100 Are All Stars the Same?
Answer Now: Why does the Sun shine? Are all stars the same as our Sun? (How or how not?) • Goal: • Be able to tell me how stars are born • Know what stars are made of • Know how stars shine • (if we have time) Know how stars die • Vocabulary:Planck curve, luminosity, H-R Diagram, absolute magnitude, apparent magnitude, fusion, H, He, CNO Cycle, protostar, nebula, protostar, hydrostatic equilibrium, interstellar medium, compression wave,
http://www4.nau.edu/meteorite/Meteorite/Images/PlanckCurve.jpghttp://www4.nau.edu/meteorite/Meteorite/Images/PlanckCurve.jpg Planck Curve - Temperature DIRECTLY related to peak wavelength.
Luminosity • Apparent magnitude • Absolute magnitude • Luminosity is the total brightness • Temperature or Type • Can tell temp from color • Can tell type from spectrum, temp or color • Types: O, B, A, F, G, K, M
http://raviramanathan.blogspot.com/2007/05/life-cycle-of-star.htmlhttp://raviramanathan.blogspot.com/2007/05/life-cycle-of-star.html
It all starts with gas • Interstellar medium • Gas cloud (nebula) • Compression wave • Pockets of compacted gas • Gravity further squeezes gas • PROTOSTAR! • Squished enough (enough energy) fusion begins • STAR!
E=mc2 H+H+H+H+H+H = He + H + H+ energy
Hydrostatic Equilibrium Energy from fusion
Compression Wave: http://video.google.com/videoplay?docid=-6732533372822687572&ei=c_iASe30OZ64qAPS-MSVDg&q=slinky+compression&hl=en
And in the end… • < 4 Solar Mass – when finished fusing H, begins to fuse He • Ffffffft (planetary nebula) • White dwarf/black dwarf • > 4 Solar Mass – when finished fusing H, begins to fuse He – when finished fusing He, begins to fuse C, N, O (shells) • Kerblewie! (supernova) • Black hole/neutron star
Review – define 3 of the terms at the beginning of this lecture. • Quiz Review
“High Mass Stars” My candle burns at both ends;It will not last the night;But ah, my foes, and oh, my friends--It gives a lovely light. Emily Dickinson