Download Ay 123 Lecture 12 - Modeling Stellar Evolution

Ay 123 Lecture 12 - Modeling Stellar Evolution
Hayashi track for
pre-MS evolution:
Proto-stars follow
track of declining
luminosity at fixed
temperature
Area to the right of
the track is
`forbidden’ in sense
of not being in HS
equilibrium
Pre-Main
Sequence
Evolution and
Timescales
Main Sequence and
Post Main Sequence
Evolution and Timescales:
Shell Burning and Transition to Red Giant Phase
• Shell burning maintains a fixed location within a star
• Collapse of core is accompanied by envelope expansion