Exploding spoonfuls of white dwarf stars

[MKruer]

This one comes from another thread. Everyone should have heard that a white dwarf is so dense that one spoonful would weight several tons. This is because the gravitational pull is so great that the elements have crushed themselves together and are now being held up by Electron degeneracy pressure.

So my question is this. If you could take a spoonful of matter away from the star would that spoonful of matter explode because the gravitational forces are now weaker that the other forces come back into effect?

[Fenerit]

I believe yes. It should resemble how the matter has gone to form that stellar stage. More explosive in the case of a neutron star. Or not?

[MKruer]

Thanks for the conformation; that?€™s what I thought. Yes a Neutron Star would be even worse because instead of having the mass of a star in the ball size of a planet, it instead would be in a ball the size of New York (~10 km)

[Fenerit]

Naturally, more than the explosive event per se like an H bomb, are the neutrinos, X and gamma rays spreads, to which we should see in considering the thing; even from a thermodinamical point of view; that is, from an high entropy situation of the spoonful in the stellar body to a low entropy situation of the spoonful out of the stellar body. (entalpic function or entalpic order). This fact maintain the so-called "arrow of time".

[MKruer]

Huh?
So ... like it would explode so completely that it would only emit partials at the high end of the electromagnetic spectrum, namely gama rays.

[Fenerit]

To say, but with a lot of imprecision, the spoonful behave more as an annihilation than a "bomb". An H bomb has the explosion which has on Earth because it happen on "air". Into the void an H explosion is "visually" a little different. (don't think at matter, this latter is converted in energy ). For what concern the spectrum, sure: consider how the gamma rays are pertinent to the Black Hole's vaporization because beyond the blu there is the black, no? The gamma rays are the same, does changes only their energy.

[Fenerit]

Just a precisation about "beyond the blue there is the black", since in the spectrum the black is also beyond the red; in this case is matter of gravitational waves.

[ajtribick]

If we take Sirius B, with a radius similar to Earth and a mass similar to the Sun, we get an average density of 2x10^9 kg/m^3, as opposed to the density of graphite of about 2x10^3 kg/m^3, or carbon monoxide at 1 kg/m^3. (very approximate numbers)

Naively we would therefore expect an expansion in volume by a factor of ~10^6 (corresponds to multiplying the lengths up by a factor of ~100), but I wouldn't want to say how quickly this would happen.

Then again, matter taken from the surface or the core may well have different amounts of compression.

What would happen if you removed neutron matter from a neutron star is complicated by the fact that you'd get beta decay of the neutrons going on, plus any scale expansion. Then again, what's actually going on in such stars isn't well known.