What is degeneracy pressure caused by?
Once the lowest energy level is filled, the other electrons are forced into higher and higher energy states resulting in them travelling at progressively faster speeds. These fast moving electrons create a pressure (electron degeneracy pressure) which is capable of supporting a star!
What is meant by degeneracy pressure?
[ dĭ-jĕn′ər-ə-sē ] A pressure exerted by dense material consisting of fermions (such as electrons in a white dwarf star). This pressure is explained in terms of the Pauli exclusion principle, which requires that no two fermions be in the same quantum state.
What stars have degeneracy pressure?
Brown dwarfs are entirely supported by degenerate pressure. The burned-out core of a star supported against gravitational collapse by degenerate electrons is called a white dwarf. You cannot support a star more massive than 1.4 solar masses by degenerate electron pressure.
What does electron degeneracy pressure do in a star’s life?
Electron degeneracy pressure will halt the gravitational collapse of a star if its mass is below the Chandrasekhar limit (1.44 solar masses). This is the pressure that prevents a white dwarf star from collapsing.
How is electron degeneracy pressure overcome?
In the core, the force of gravity is sufficient to overcome the electron degeneracy pressure, and the electrons are driven into the atomic nuclei. Each electron combines with a proton, producing a massive sphere of neutrons.
Under what conditions does electron degeneracy occur?
Electron degeneracy occurs when matter is compressed to the point that electrons fill the lowest quantum states, forming electron degenerate matter (EDM). The Pauli exclusion principle dictates that within a sufficiently small volume, at most one electron can be at any specific state.
What remains after a supernova?
Supernovae are thus essential to life. After a core collapse supernova, all that remains is a dense core and hot gas called a nebula. When stars are especially large, the core collapses into a black hole. Otherwise, the core becomes an ultra-dense neutron star.
How does degeneracy pressure differ from thermal pressure?
Unlike thermal pressure, degeneracy pressure depends only on density and not on temperature. Since degeneracy pressure does not weaken as the core cools, it will continue to support a core even when the core becomes cold.
What does it mean for a star to be degenerate?
A star that has collapsed to a high density so that degeneracy pressure is its main support against further collapse.
What happens when the gravity of a star overcomes electron degeneracy pressure?
The force of gravity was enough to overcome the electron degeneracy pressure, and the star would collapse into an even denser state. Stars more massive than approximately 5-7 times the mass of the Sun don’t become giants – they become supergiants.
What happens when gravity overcomes neutron degeneracy pressure?
What happens when the gravity of a massive star is able to overcome neutron degeneracy pressure? The star explodes violently, leaving nothing behind. The core contracts and becomes a white dwarf.
What are the effects of a supernova?
Supernovae, the explosions of stars, have been the main focus. A really nearby event — 30 light-years away or closer — would induce a mass extinction from radiation destroying the ozone layer, allowing lots of ultraviolet radiation through to damage life on the surface.