Neutron star and white dwarf material

[mathman]

Neutron stars are held together by extremely strong gravitational force. What would happen to a chunk of the star if it had been removed and left to stand alone?

Same question for a chunk of a white dwarf?

 

[Chronos]

Either would be unstable once removed from the gravitational well. 'Boom' is probably the word I'm looking for.

 

[phinds]

'Boom' is probably the word I'm looking for.

 

[Drakkith]

Neutron stars are held together by extremely strong gravitational force. What would happen to a chunk of the star if it had been removed and left to stand alone?

Same question for a chunk of a white dwarf?

The outer crust of a Neutron star is thought to be composed of mostly ions and electrons, not neutrons. I expect that the matter would no longer be degenerate and would quickly form normal atoms again. Since atoms release energy when electrons bind with nuclei, I would expect a very large chemical explosion. Same thing for a white dwarf.

 

[Chronos]

The crust of a neutron star is probably iron, as I recall. And I believe the result would be more on the order of a nuclear explosion - just my guess. I would hate to have the job of mining material from either object. The scoop design would be problematic and the workmans comp insurance premiums - priceless.

 

[Drakkith]

Why do you think there would be a nuclear explosion from the removal of surface material?

 

[Chronos]

Chemical processes do not occur at these energy levels.

 

[Drakkith]

If the nuclei are stable then what kind of nuclear processes are we talking about here?

 

[mathman]

To rephrase my question slightly. Assume we could get material from deep in the interior of the neutron star or white dwarf. What happens?

 

[Drakkith]

Without being educated in this area I can only guess, but I'd say probably some kind of explosion. I know in a white dwarf that many of the electrons have high kinetic energy. From wikipedia:

This state of the electrons, called degenerate, meant that a white dwarf could cool to zero temperature and still possesses high energy. Another way of deriving this result is by use of the uncertainty principle: the high density of electrons in a white dwarf means that their positions are relatively localized, creating a corresponding uncertainty in their momenta. This means that some electrons must have high momentum and hence high kinetic energy.[38][40]

Compression of a white dwarf will increase the number of electrons in a given volume. Applying either the Pauli exclusion principle or the uncertainty principle, we can see that this will increase the kinetic energy of the electrons, causing pressure.[38][41] This electron degeneracy pressure is what supports a white dwarf against gravitational collapse. It depends only on density and not on temperature. Degenerate matter is relatively compressible; this means that the density of a high-mass white dwarf is so much greater than that of a low-mass white dwarf that the radius of a white dwarf decreases as its mass increases.[1]

I assume that the removal of pressure from the material would result in a great release of energy as the matter violently expands and high energy electrons run into other particles.

As for neutron stars I would expect something similar in addition to neutron decay once the extreme pressure is removed.