NATS 1740 Lecture Notes - Lecture 1: Nuclear Fusion, Convection Zone, Radiation Zone

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Michael De Robertis, Alireza Rafiee

Document Summary

Gravitational equilibrium: gravity pulling in balances pressure pushing out. Energy balance: thermal energy released by fusion in core balances radiative energy lost from surface. Gravitational contraction => provide energy that heated the core as the sun was forming. Contraction stopped when fusion started replacing the energy radiated into space. => chemical + gravitational energy sources cannot explain. => nuclear fusion in the core maintains gravitational equilibrium (between pressure and gravity) + energy balance (between thermal energy released in core) and radiative energy lost from the. Structure of the sun from outside to inside. Solar wind: a flow of charged particles from the surface of the sun. Corona: outermost layer of solar atmosphere ~ 1 million k. Photosphere: visible surface of the sun ~ 6000k. Convection zone: energy transported upward by rising hot gas. Radiation zone: energy transported upward by photons.