AST 309 Lecture Notes - Lecture 12: Low Mass, Hayashi Track, Protostar
Document Summary
Hayashi tracks - evolution onto the main sequence. Once the reservoir that feeds the disks has gone away the disks can no longer be replenished. Left with smaller circumstellar disks and debris disks, building blocks for planets. Planet building most active in last stage - class iii. The path stars takes to the main sequence - hayashi tracks. Theoretical models for how stars evolve onto the main sequence. Path stars move on hr diagram to get to ms. Tracks are different depending on mass of protostar. Involves evolution from stages 4-6 in star formation process. Bigger stars take less time to reach ms, smaller stars take longer. For lower and intermediate mass stars, like the sun, while on the hayashi. Track, the star is mostly or completely convective. During this time, the star maintains a relatively constant maintains a relatively constant temperature and luminosity as the star shrinks.
