Learning Goals . . . .PowerPoint PresentationStefan-Boltzmann LawSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Kirchhoff’s LawsSlide 11Where is the “cooler, lower-density cloud” in a star?Slide 13Slide 14Slide 15Slide 16Universe is full of things that look like stars!One of these things is not like the others . . . .Slide 19Slide 20Cause for confusion: what about how the spectra looked different because of chemical abundances, such as we learned about in the spectral analysis lab?Slide 22Slide 23Slide 241Explain how knowledge of Stefan-Boltzmann law leads to understanding of temperatures and radii of stars.Summarize the circumstances under which objects produce thermal (continuous), emission line, or absorption line spectra.Explain what is meant by the spectral sequence of stars.Learning Goals . . . .Learning Goals . . . .2 How does the Stefan-Boltzmann law lead to our understanding of temperatures and radii of stars?Summarize the circumstances under which objects produce thermal (continuous), emission line, or absorption line spectra.Explain what is meant by the spectral sequence of stars.3 Explain how knowledge of Stefan-Boltzmann law leads to understanding of temperatures and radii of stars.€ L = 4πR2σT4Stefan-Boltzmann LawStefan-Boltzmann Law41. Between A and C (large and warm, small and warm), which one will boil water first?2. Between A and B, which one will boil water first?3. Between B and D (large and medium, small and hot), which one will boil water first? ABCDCoils of same color have same TemperatureABCD€ L ∝ R2T45QuickTime™ and a decompressorare needed to see this picture.A BCD€ L = 4πR2σT46Applying to stars€ L = 4πR2σT4L4πσT4= R2R =L4πσT4We have ways of finding L (luminosity).7How does the Stefan-Boltzmann law lead to our understanding of temperatures and radii of stars?8QuickTime™ and a decompressorare needed to see this picture.http://www.youtube.com/watch?v=bov9M2gEgcE9 Explain how knowledge of Stefan-Boltzmann law leads to understanding of temperatures and radii of stars.Summarize the circumstances under which objects produce thermal, emission line, or absorption line spectra.Explain what is meant by the spectral sequence of stars.10Kirchhoff’s LawsKirchhoff’s Laws11QuickTime™ and a decompressorare needed to see this picture.QuickTime™ and a decompressorare needed to see this picture.QuickTime™ and a decompressorare needed to see this picture.Production of an emission line spectrumProduction of a continuous spectrumIllustrating the geometry needed to view each of the kinds of spectra12Where is the “cooler, lower-density cloud” in a Where is the “cooler, lower-density cloud” in a star?star?QuickTime™ and a decompressorare needed to see this picture.??QuickTime™ and a decompressorare needed to see this picture.Core: 17,000,000 K “Surface”: 6,000 K“Absorption Layer”: 4,000 K13Putting filters to practical use:14Putting Kirchhoff’s laws to practical use when observing Helix nebula:1. Absorption2. Emission3. Continuous A. White DwarfB. Diffuse GasC. Distant star behind cooler gas15Summarize the circumstances under which objects produce thermal, emission line, or absorption line spectra.16Explain how knowledge of Stefan-Boltzmann law leads to understanding of temperatures and radii of stars.Summarize the circumstances under which objects produce thermal (continuous), emission line, or absorption line spectra.Explain what is meant by the spectral sequence of stars.OO BB AA FF GG KK MM L L T TOO BB AA FF GG KK MM L L T T17Universe is full of things that look like stars!Universe is full of things that look like stars!QuickTime™ and a decompressorare needed to see this picture.Pluto & Charon18One of these things is not like the others . . . .One of these things is not like the others . . . .19 Explain what is meant by the spectral sequence of stars20 Explain what is meant by the spectral sequence of stars21Cause for confusion:Cause for confusion: what about how the spectra looked what about how the spectra looked different because of chemical abundances, such as we different because of chemical abundances, such as we learned about in the spectral analysis lab?learned about in the spectral analysis lab?220 1 2 3 4 5 6 7 8 90 1 2 3 4 5 6 7 8 90 1 2 3 4 5 6 7 8 90 1 2 3 4 5 6 7 8 90 1 2 3 4 5 6 7 8 90 1 2 3 4 5 6 7 8 90 1 2 3 4 5 6 7 8 9 Explain what is meant by the spectral sequence of starshttp://www.astro.uiuc.edu/~kaler/sow/class-g.html23 Explain what is meant by the spectral sequence of stars24Explain what is meant by the spectral sequence of stars.OO BB AA FF GG KK MM L L T TOO BB AA FF GG KK MM L L T
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