NATS 1740 Lecture Notes - Electron Degeneracy Pressure, White Dwarf, Degenerate Matter

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Randy Hoffman

Document Summary

White dwarf: exposed core of a star that has died and shed its outer layers. Have masses of stars but radii of earth (very dim) Support by electron degeneracy pressure (packed electrons push outward) A teaspoon of white dwarf matter would weigh several tons. White dwarf formed by stars like our son would leave behind carbon. Low mass stars form white dwarfs with helium. More massive white dwarfs are smaller in size. No white dwarf can have mass greater than 1. 4m sun. In a close binary system, gas from a companion star can spill toward a white dwarf forming an accretion disk (new energy source) around it. A nova is caused by hydrogen fusion on the surface of a white dwarf in a binary star system. 100,000 times as bright as sun, shines for a few weeks, not as bright as a supernova. When it reaches 1. 4m of the sun carbon is ignited and star explodes.