AS101 Lecture Notes - Lecture 10: Thermostat, Main Sequence
Document Summary
Cno (carbon nitrogen oxygen) cycle: a series of nuclear reactions that use carbon as a catalyst to combine four hydrogen nuclei to make one helium nucleus plus energy. Solar neutrino problem: observations of too few neutrinos coming from the suns core. The relationship the pressure temperature thermostat, ensures that stars generate just enough energy to be stable between pressure temperature, called: too much energy: star expands central temperature decreases nuclear and reactions decrease stability regained, too little energy star contracts central temperature increase nuclear reactions increase stability regained. Objects with masses less than about 0. 08 solar masses are unable to start nuclear fusion in their cores. Stars enter the main sequence once they start fusing hydrogen and reach stability zero age main sequence (zams) the right on the h r diagram. As they grow older, and exhaust their fuel, stars move upward and slightly to.
