Transcript Solar Interior - University of Washington

The Sun
Our star - inside and out
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Earth having a really, really bad day.
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Learning Goals:
Explain the proton-proton cycle in easy-tounderstand language.
State how radiation is transported through each
region of the Sun’s interior
Explain how the Sun maintains a constant
balance in its interior (solar thermostat)
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LIGHT!
LIGHT!
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Core
Proton-Proton Cycle
e-
g
• 1H + 1H --> 2H + e+ + neutrino
•
2H
+
1H
-->
3He
+ gamma ray
n
g
Must
occur
twice
• 3He + 3He --> 4He + 1H + 1H
0.007 of original mass is converted to energy
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Explain the proton-proton cycle in easy-to-understand language.
I hate you,
proton. You are
so repulsive.
You reek! Stay
away, you
positive jerk.
Protons must collide at high velocities:
+
+Temperature must be > 10,000,000 Kelvin
Plasma must be extremely dense.
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Explain the proton-proton cycle in easy-to-understand language.
Explain the proton-proton cycle in
easy-to-understand language.
a. Two helium-3 nuclei collide and
fuse to form the more common
form of the element: helium-4.
b. At the instant the nuclei fuse and
create a deuterium nucleus, a
positron and a neutrino are
created.
c. Two protons (H nuclei) meet under
the extreme conditions present in
the core of the Sun.
d. Positron + electron = annihilation;
masses convert to energy in form
of 2 gamma ray photons.
e. Two extra protons are released,
available for further nuclear
reactions.
f. In about 6 seconds a 3rd proton
fuses with deuterium nucleus7to
form He-3 + gamma ray.
http://en.wikipedia.org/wiki/Random_walk
PASS YOUR SHEETS TO THE
CENTER AISLE
DEMONSTRATION OF THE
RANDOM WALK WILL TAKE
PLACE WHILE YOU ARE
HANDING IN YOUR SHEETS.
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Radiative Zone
Random Walk
State how radiation is transported through each region of the Sun’s interior
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Convection Zone
A
Granulation
A
CONVECTION MOVIE
State how radiation is transported through each region of the Sun’s interior
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State how radiation is transported through each region of the Sun’s
interior
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Hydrostatic (gravitational) equilibrium in the Sun
maintains a constant balance between inwardpushing gravity and outward-pressing pressure.
Another way of thinking about this:
The Solar Thermostat
QuickTime™ and a
decompressor
are needed to see this picture.
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Explain how the Sun maintains a constant balance in its interior (solar thermostat)
Number of particles in core is decreasing.
NET RESULT
IN: 6 H
OUT: 1 He + 2 H
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Explain how the Sun maintains a constant balance in its interior (solar thermostat)
Explain how the Sun maintains a constant balance in its interior
(solar thermostat)
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