01:750:109 Chapter Notes - Chapter 9.2: Red Giant, Protostar, Main Sequence
Document Summary
Will analyze what happens once core hydrogen runs out and a star can no longer remain in balance. Like everything else in a star"s life, its fate when it runs out of core hydrogen depends on its mass. Scientists learn about the end stages of stellar lives through a combo of theoretical modeling and observations of stars that appear to be in these late stages. These studies show that stars divide into 2 major groups by mass: Low-mass stars, like our sun, end their lives relatively quietly. High-mass stars (more than 8m sun ) die in titanic explosions. When sun"s core hydrogen is finally depleted, nuclear fusion in core will temporarily cease. Sun"s outer layers will expand outwards during this time (surprisingly) Over a billion yrs (about 10% of its main sequence lifetime) the sun will slowly grow in size and luminosity to become a red giant.