AST201H1 Chapter Notes - Chapter 18.1-18.2 : Astronomical Object, Triple-Alpha Process, Degenerate Matter

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Bryan Gaensler

Document Summary

Exposed core of a star that has died and shed outer layers in planetary nebular. Stellar in mass but small in size (radius) No fusion --> gravity must come from somewhere else --> degeneracy pressure. Type of pressure that arises when subatomic particles are packed as closely as the laws of quantum mechanics allow. Mass of sun compressed in volume the size of earth --> extremely high density. More massive is smaller in size (more compressed) Can gradually gain mass if its companion is a main-sequence or giant star. Orbital velocity from spillover, will orbit faster and faster as it falls towards white dwarf"s surface. Gradually spirals inwards and settles onto white dwarf. Can create new energy source if companion keeps feeding matter into accretion disk. Heat generated by friction can make the accretion disk hot enough to radiate visible and ultraviolet light. Hydrogen gas compressed onto a thin surface layer, pressure and temperature rises as layer grows.