ASTRON 1010 Lecture Notes - Lecture 21: Accretion Disk, White Dwarf, Subgiant
Document Summary
A star"s mass determines its entire life store to make iron, and end in supernova explosions. High mass stars with >8m have short lives, eventually becoming hot enough. Low-mass stars with <2m have long lives, never become hot enough to fuse carbon nuclei, and end as white dwarfs. Intermediate-mass stars can make elements heavier than carbon but still end as white dwarfs. The binary star algol: consists of a 3. 7m main-sequence star and a 0. 8m subgiant star. Stars in a binary system can sometimes exchange mass. Stars in algol are close enough that matter can flow from the subgiant onto the main-sequence star. The star that is now a subgiant was originally more massive. As it reached the end of its life and expanded, it began to transfer mass to its companion. Now the companion star is more massive. A star"s mass determines its life story: protostar, time on the main sequence,
