*THIS IS A TEMP NOTE FOR VARIOUS DIFFERENT STELLAR REMNANTS AND WILL BE RESTRUCTURED IN THE FUTURE.* # Understanding how Stars die Nothing lives forever. Loved ones pass on, trees are felled, wasp nests are eaten whole and raw - the circle of life permeates the choices we make with our lives. However, <0.01 planet 0.01 - 0.08 rown dwarf 0.08-0.25 helium white dwarf 0.25- 4 carbon-oxygen white dwarf 4-8 oxygen-neon-magnesium whit edwarf 8-20 neutron star supernova 20+ black hole supernova a [[White Dwarves (Astro)|white dwarf]] is a **degenerate core**, stars shed off a good half of their mass when they turn into white dwarves (what they become depends on. their masses) brown dwarf --> not massive enough to fuse hydrogen, but can fuse deuterium (failed star) ## The Death of Low-Mass Stars - the entire star convects ,meaning that their lifetimes are much greater than the age of the universe (>10 trillion yrs) - stars can never fuse helium --> too light, can just convect the hydrogen supply - predicted scenario --> red dwarfs heat up and become bluer as they burn through their supply of H - they will become helium white dwarfs which cool into black dwarfs over long periods of time ## The Death of Sun-Like Stars Depending on the star's mass it will end its life as a white dwarf (WD) made of different elements - 0.1-0.7 solar masses - helium WD - 0.7-4 solar masses - carbon WD - 4-8 solar masses - oxygen, neon, magnesium WD thermal pulses will force the // the death of massive stars 8 - 20 solar masses: Neutron star 20+ solar masses: black hole these stars also start by fusing H in the core (mostly through CNO) then He, and on to heavier and heavier elements which sink to the core in layers once iron is created by fusion, the star's collapse is imminent. fusing iron does not release more energy the way fusing H or He does - it takes energy. this means gravity takes over and the star starts to collapse The iron core collapses very fast creating a very high density core;. A shock wave travels outward from the core w/ a high number of neutrinos the star explodes thanks to the outer layers bouncing off the core of the star