White dwarf

[CedrikG]

hey folks

Little question. In a super nova, the gaz compressing the core of the sun is so violent and so intense that it break the atom, leaving being a ball of super condensed neutron, a Neutron star.

I was wondering what was the material inside a White dwarf, created from a Nova... Are the atom broken ?

[LukeSkywatcher]

http://en.wikipedia.org/wiki/White_dwarf

[michael.h.f.wilkinson]

In a white dwarf the matter is degenerate. Pressure is insufficient to force the electrons into the nuclei creating a neutron star. Instead, they are as closely packed as the Fermi exclusion principle allows.

[NeutronNick]

Degenerate electrons, which within the WD keep gravity at bay via hydrostatic equilibrium. However if the WD is a binary (or more) and is close enough, normally a giant, then gas (mainly hydrogen etc) is accreted to the surface of the WD. Over time pressure and gravity increase causing previously unfused carbon within the WD to detonate, known as carbon detonation, causing a type 1A SN. This will only happen if around 1.39 solar masses is exceeded (Chandrasekhar limit).