Neutron star and white dwarf material

In summary, a chunk of a neutron star or white dwarf would be unstable once removed from the gravitational well. 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. 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.
  • #1
mathman
Science Advisor
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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?
 
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  • #2
Either would be unstable once removed from the gravitational well. 'Boom' is probably the word I'm looking for.
 
  • #3
Chronos said:
'Boom' is probably the word I'm looking for.

:rofl:
 
  • #4
mathman said:
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.
 
  • #5
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.
 
  • #6
Why do you think there would be a nuclear explosion from the removal of surface material?
 
  • #7
Chemical processes do not occur at these energy levels.
 
  • #8
If the nuclei are stable then what kind of nuclear processes are we talking about here?
 
  • #9
To rephrase my question slightly. Assume we could get material from deep in the interior of the neutron star or white dwarf. What happens?
 
  • #10
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.
 

What is the difference between a neutron star and a white dwarf?

A neutron star is a highly dense, collapsed star made up of mostly neutrons. It is formed from the core of a massive star after a supernova explosion. A white dwarf, on the other hand, is a star that has exhausted its nuclear fuel and collapsed to a dense, hot core. It is the final stage of evolution for stars with a mass similar to the sun.

What is the material composition of a neutron star?

Neutron stars are composed mainly of neutrons, which are subatomic particles with no charge. They are incredibly dense, with a mass comparable to that of the sun condensed into a sphere the size of a city. In addition to neutrons, neutron stars also contain a small amount of protons, electrons, and other subatomic particles.

What happens to the material inside a white dwarf?

As a white dwarf forms, the core of the star becomes very dense, with the electrons in the atoms being pushed closer together. Eventually, the electrons become so tightly packed that they are unable to be compressed any further, creating a degenerate electron gas. This gas supports the outer layers of the star, preventing it from collapsing further.

Can neutron star and white dwarf material be found on Earth?

While neutron stars and white dwarfs are not found on Earth, scientists can study their material through observations and experiments. For example, scientists can study the radiation emitted by neutron stars and use this information to learn about their composition. Additionally, scientists can create conditions similar to those found in neutron stars and white dwarfs in laboratories, allowing them to study the behavior and properties of their material.

Can white dwarf material ever become a neutron star?

No, white dwarf material cannot become a neutron star. In order for a star to become a neutron star, it must have a mass at least 1.4 times that of the sun. White dwarfs, on the other hand, have a maximum mass of about 1.4 times the mass of the sun. Once a star becomes a white dwarf, it will eventually cool and fade away, rather than collapsing further into a neutron star.

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