NATS 1740 Lecture Notes - Lecture 12: White Dwarf, Degenerate Matter, Binary System

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Michael De Robertis, Alireza Rafiee

Document Summary

Very tiny in size but huge in mass. White dwarfs are the remaining cores of dead stars. Electron degeneracy pressure supports them against gravity. White dwarfs cool off and grow dimmer with time. If it"s smaller than < 45% mass of the sun, it may stay in main sequence very long time (+) size. Incredibly massive, condense into a small are. White mass with the same mass as the sun are about the same size as earth. Higher-mass white dwarfs are smaller, there is the limit speed of light, increase the mass => they have to move faster (+) the white dwarf limit. Quantum mechanics state that electrons must move faster as they are squeezed into very small space. As a white dwarf"s mass reach 1. 4m. sun, its electrons must move at nearly the speed of light. Because nothing can move faster than light, a white dwarf cannot be more massive than. 15% of the stars are in binary system.