nobel prize in physics for accelerating...
TRANSCRIPT
![Page 1: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/1.jpg)
Nobel Prize in Physics for
Accelerating Universe
• Awarded to Saul Perlmutter, Adam Riess, and Brian Schmidt for finding that the expansion of the Universe is accelerating rather than decelerating.
• First published in 1998.
![Page 2: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/2.jpg)
Ocean-like water in the comet 103P/Hartley 2
• Astronomer have found that comet Hartley 2 contains water similar to the water we find on Earth.
• “Similar” means that the fraction of heavy water is same as in our oceans.
• Heavy water is D2O instead of H
2O, where D is deuterium
which has a nucleus with one proton and one neutron.
• The comet comes from the Kupier belt (30-50 AU) while most comets come from the Oort cloud (> 5000 AU).
![Page 3: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/3.jpg)
How Stars Evolve
• The fate of the Sun– Nuclear ash– Red giant phase– Planetary nebula– White dwarf
• Ages of star clusters
![Page 4: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/4.jpg)
What would happen to a contracting cloud fragment if it were not able to radiate away its thermal energy?
A. It would continue contracting, but its temperature would not change
B. Its mass would increaseC. Its internal temperature would increaseD. It would be happy
![Page 5: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/5.jpg)
The Fate of the Sun
• How will the Sun evolve over time?• What will be its eventual fate?
![Page 6: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/6.jpg)
Sun’s Structure
• Core– Where nuclear fusion
occurs
• Envelope– Supplies gravity to keep
core hot and dense
![Page 7: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/7.jpg)
Main Sequence Evolution
• Core starts with same fraction of hydrogen as whole star
• Fusion changes H → He
• Core gradually shrinks and Sun gets hotter and more luminous
![Page 8: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/8.jpg)
Gradual change in size of Sun
Now 40% brighter, 6% larger, 5% hotter
![Page 9: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/9.jpg)
Main Sequence Evolution
• Fusion changes H → He
• Core depletes of H• Eventually there is not
enough H to maintain energy generation in the core
• Core starts to collapse
![Page 10: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/10.jpg)
Red Giant Phase
• He core– No nuclear fusion– Gravitational contraction
produces energy
• H layer– Nuclear fusion
• Envelope– Expands because of
increased energy production– Cools because of increased
surface area
![Page 11: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/11.jpg)
Sun’s Red Giant Phase
![Page 12: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/12.jpg)
HR diagram
Giant phase is when core has been fully converted to Helium
![Page 13: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/13.jpg)
When hydrogen burning in the core stops, a star like the Sun begins to evolve
A) To higher surface temperature and higher luminosity
B) To lower surface temperature and higher luminosity
C) To higher surface temperature and lower luminosity
D) To lower surface temperature and lower luminosity
E) Up the main sequence to become an O star
![Page 14: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/14.jpg)
Helium Flash• He core
– Eventually the core gets hot enough to fuse Helium into Carbon.
– This causes the temperature to increase rapidly to 300 million K and there’s a sudden flash when a large part of the Helium gets burned all at once.
– We don’t see this flash because it’s buried inside the Sun.
• H layer• Envelope
![Page 15: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/15.jpg)
After Helium Ignition
• He burning core– Fusion burns He into C, O
• He rich core– No fusion
• H burning shell– Fusion burns H into He
• Envelope– Expands because of
increased energy production
![Page 16: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/16.jpg)
Movement on HR diagramMovement on HR diagram
![Page 17: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/17.jpg)
The Life of the Sun
![Page 18: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/18.jpg)
During double shell burning Sun loses mass via winds
• Creates a “planetary nebula”
• Leaves behind core of carbon and oxygen surrounded by thin shell of hydrogen – a white dwarf
![Page 19: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/19.jpg)
White dwarf
• Star burns up rest of hydrogen• Nothing remains but degenerate core of Oxygen
and Carbon• “White dwarf” cools but does not contract
because core is degenerate• No energy from fusion, no energy from
gravitational contraction• White dwarf slowly fades away…
![Page 20: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/20.jpg)
![Page 21: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/21.jpg)
Planetary nebula
![Page 22: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/22.jpg)
Planetary nebula
![Page 23: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/23.jpg)
Hourglass nebula
![Page 24: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/24.jpg)
Which property of a star controls its formation, evolution, and demise?
A) LuminosityB) MassC) RadiusD) Temperature
![Page 25: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/25.jpg)
Once the core of a star ends hydrogen fusion, the core
A) expands and gets hotterB) shrinks and gets hotterC) expands and gets coolerD) shrinks and gets cooler
![Page 26: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/26.jpg)
Planetary nebulae are mostly composed of
A) hydrogen.B) helium.C) carbon.D) oxygen.
![Page 27: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/27.jpg)
How can we determine the age of a star cluster?
![Page 28: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/28.jpg)
Formation time for different masses
• High-mass stars form fast
• Low-mass stars form slowly
![Page 29: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/29.jpg)
Time on main
sequence is set by
mass
![Page 30: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/30.jpg)
Turn-off point of cluster reveals age
![Page 31: Nobel Prize in Physics for Accelerating Universeastro.physics.uiowa.edu/~kaaret/f11/L11_starsevolve.pdfNobel Prize in Physics for Accelerating Universe • Awarded to Saul Perlmutter,](https://reader034.vdocuments.us/reader034/viewer/2022050113/5f4a25857417be3b3940ea2a/html5/thumbnails/31.jpg)
Review Questions
• What are the main stages in the evolution of solar mass star?
• What causes the star to move from one stage to the next?
• What does a solar mass star leave as a remnant?
• How can you determine the age of a star cluster?