ASTR 20 Lecture Notes - Lecture 24: Zeeman Effect, Sudbury Neutrino Observatory, Solar Neutrino Problem
Document Summary
Decline in core temperature causes fusion rate to drop, so core contracts and heats up. Rise in core temperature causes fusion rate to rise, so core expands and cools down. Fusion energy= amount of energy radiated from the surface. Energy gradually leaks out of the radiation zone in the form of randomly bouncing photons. Outside of radiation zone, plasma has cooled enough to absorb photons. Convection (rising hot gas) takes energy to the surface. At the top of the convection zone, the density of gas is low enough for photons to escape into space and travel to earth (8 minutes) How long does it take energy originally produced by fusion at the center of the sun to make it to earth: 100,00 years. How do we know what is happening inside the sun: making mathematical models. We know the physical processes- fusion, radiation, convection, gravitational equilibrium.
