AST 341 Lecture Notes - Lecture 20: Angular Velocity, Urca, Position And Momentum Space

• School: Stony Brook University
• Department: Astronomy
• Course: AST 341
• Professor: Rosalba Perna

Document Summary

We have seen that for very large electron densities leading to relativistic degeneracy we reach a mass limit for white dwarfs. For larger masses, gravitational forces are larger than the electron degeneracy pressure, and the star shrinks. On the other hand, we have seen from our discussion of supernovae that for very high densities the electrons and protons reach densities so high that protons and electrons combine to form neutrons (p+e . We then no longer have degenerate electrons, but degenerate neutrons. Because of the larger mass of neutrons as compared to electrons, the degeneracy starts only at much high densities, but for su ciently high densities we also nd neutron degeneracy. The existence of such exotic objects as neutron stars was rst postulated by lev landou as early as 1932. Landou mentioned the possible formation of one gigantic nucleus, when atomic nuclei come in close contact in star exceeding the critical mass.