01:750:109 Chapter Notes - Chapter 9.2: Carbon-Burning Process, Solar Mass, Main Sequence
Document Summary
At first, end stages very similar to those of low-mass star, except proceed much more rapidly. Ex: 25 solar mass star lasts only a few million yrs as a hydrogen fusing main sequence star before it goes out of balance. As its core hydrogen runs out, a hydrogen fusing shell forms around a shrinking helium core, generating so much energy that the star"s outer layers expand outward until the star becomes a supergiant . Then, helium into care so rapidly that it is left w an inert carbon core after no more than a few hundred thousand yrs. After this stage, the life stages become quite diff from those of the sun. Gravitational contraction simply continues after carbon fusion ends, the inert carbon core shrinks, and the core pressure, temp, and density all rise. As each stage of core fusion ceases, the surrounding shell fusion intensifies and further inflates the stat"s outer layers.