ASTRON 100 Lecture Notes - Solar Neutrino Problem, Zeeman Effect, Potential Energy
21 Jan 2014
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Document Summary
The sun is not on fire: chemical energy / total luminosity= 10,000 years. The sun is not contracting: gravitational potential energy / luminosity = 25 million years. The sun is powered by nuclear energy (e=mc^2) Nuclear potential energy (core) / luminosity = 10 billion years. Weight of upper layers compresses lower layers. Energy supplied by fusion maintains the pressure that balances the inward crush of. The rate at which energy radiates from the surface of the sun must be the same as the rate at which it is released by fusion in the core. Radius: 6. 9 x 10^8 m (109 times the earth) Core: energy generated by nuclear fusion = 1 million k. Convection zone: energy transported upward by hot rising gas. Photosphere: visible surface of the sun = 6000 k. Chromosphere: middle layer of the solar atmosphere = 10^4-10^5 k. Corona: outermost layer of the solar atmosphere = 1 million k.
