Degenerate Pressure Can End Fusion
• Degenerate Electron Pressure limits contraction and core
– “Stars” with M < 0.08 MSun never burn H    (brown dwarfs)
– Stars    with M < 0.4   MSun never burn He   (red dwarfs)
– Stars    with M < 4      MSun never burn C     (but do make red giants)
– Stars    with M > 4      MSun do burn elements all the way to Fe
• What happens to these objects?
– Brown dwarfs never become bright – sort of like giant version of Jupiter
– Red dwarfs have such long lives none have yet exhausted H
– Red giants are related to white dwarfs
– Massive stars explode as supernova