ASTR BC 1754y Lecture Notes - Lecture 10: Cno Cycle, Solar Mass, Low Mass

• School: Barnard College
• Department: Physics and Astronomy
• Course: ASTR BC 1754y
• Professor: Jacquelinevan Gorkom

Document Summary

Since massive stars live shorter they will move off the main sequence first. C, n, o only 2% of mass they act as catalysts for reaction. The more massive, the denser, the higher the pressure, the higher the temperature (in the core) Convection depends on steepness of temp gradient in star. In massive stars temp gradient is so steep that convective zone extends to the core. The ash is well mixed throughout the core. Temp in core is high enough that if they run out of h they start burning he, no degenerate core forms. Smooth transition, grows in size and temp falls. High mass stars build up layered structures, with more advanced stages of nuclear burning found deeper and deeper within the star. Neither fusion nor fission releases energy from iron because it has the lowest mass per nuclear particle.