1	Chapter 10 Our Star
2	Hydrostatic Equilibrium or Gravitational Equilibrium The outward pressure force balances the inward gravitational force everywhere inside the Sun.
3	Gravitational Equilibrium in the Sun.
4	The Sun’s Properties
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6	The Sun's Atmosphere Photosphere - "sphere of light", the visible surface of the Sun Chromosphere - "sphere of color", visible during solar eclipses Corona - the Sun's outermost atmosphere. The outflow of gas in this region is called the solar wind, which is protons and electrons that have escaped the Sun's gravity.
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14	The Basic Structure of the Sun
15	The Sun's Interior Thermonuclear core - the central region of Sun where fusion takes place due to high temperatures and pressures. Radiation zone - a region inside a star where energy is transported outward by the movement of photons (radiation). Convection zone - a layer inside a star where energy is transported outward by means of heat flow through the gasses of the star (convection).
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17	What makes the Sun shine? Thermonuclear fusion at the Sun's core is the source of the Sun's energy. 4 Hydrogen ---------> 1 Helium + Light Atoms (fusion) Atom
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22	Mass loss? 4 ´ 1 hydrogen = 6.693 ´ 10^-27kg - 1 helium = 6.645 ´ 10^-27kg ---------------------------------------------- Mass loss = 0.048 ´ 10^-27kg The missing mass is converted to pure energy ( i.e. light ) By Einstein’s energy/mass equation. E = mc²
23	What does this mean? Mass can be transformed into light. This occurs during fusion. Light be transformed into matter. This occurs in pair production. These are results from Einstein’s theory of Special Relativity.
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25	Helioseismology- Understanding the Sun’s Interior Vibrations on the surface of the Sun can be detected by Doppler shifts
26	The Neutrino Problem Standard solar model is the generally accepted theory of solar energy production. The model predicts that billions of neutrinos per second flow from the Sun. Neutrinos react very little with ordinary matter so detecting them is difficult. Neutrino telescopes indicate that only 1/3 of the neutrinos predicted by theory are “seen.”
27	Solar Neutrino “Telescopes” Solar Neutrino detector in South Dakota. Cl nuclei would turn into Ar nuclei when they captured solar neutrinos
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30	Granulation- Convection Cells in Photosphere
31	Sunspot Groups
32	Magnetic Field Lines
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34	"Solar Prominence - a flame-like..." Solar Prominence - a flame-like protrusion seen near the limb of the Sun and extending into the solar corona. These follow magnetic field lines. Solar Flare – Huge and sudden release of energy on the solar surface, probably caused when energy stored in magnetic fields is suddenly released.
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36	Solar Flare –TRACE Mission
37	Sun in X-Ray
38	Sunspot Cycle The rotation rate varies from once every 25 days to once every 30 days. This differential rotation twists the magnetic field lines. This causes the number of sunspots to vary over an 11 year period.
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40	Solar Cycle A 22 - year period that is needed for both the average number of spots and the Sun’s magnetic field polarity to repeat themselves. The Sun’s polarity reverses on each new 11-year sunspot cycle.
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44	Simmary of Surface Features Granules - convection features about 1000 kilometers in diameter seen constantly in the solar photosphere. Sunspot - a temporary cool region in the solar photosphere created by protruding magnetic fields. Prominence - a flamelike protrusion seen near the limb of the Sun and extending into the solar corona.
45	Solar Telescope
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48	End of Section