Questions tagged [degenerate-matter]

Questions regarding matter at densities so high that gravitational contraction is countered by the Pauli exclusion principle.

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Are white dwarfs made of carbon or electron degenerate matter?

I know that white dwarfs are composed primarily of carbon but are supported by electron degeneracy pressure. Is the electron degeneracy pressure produced by carbon atoms, or is the core of the white ...
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10 votes
2 answers
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Hypothetical upper and lower bounds for Chandrasekhar limit based on composition?

Disclaimer: I'm going to be using the term "white dwarf" to refer to any spherical celestial body made of electron degenerate matter. If I had a better term, I would use it. The ...
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11 votes
1 answer
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Does the average proton/electron density in a neutron star change with mass?

My understanding is that although electron degeneracy prevents beta decay, there are still a few protons and electrons hanging around. I also understand that, at least in white dwarfs, as the mass ...
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4 votes
3 answers
178 views

What escape velocity would quark stars have?

Quark stars are hypothetical compact stars that are denser than neutron stars and maybe the last stage of upholding matter before stars that collapse into a singularity. Neutron stars have escape ...
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2 votes
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Regarding core fragmentation of a gas giant in the envelope of a red giant

We know that large gas giants, such as Jupiter, have degenerate cores. Let's say there is a hot Jupiter ($5M_J$) that orbits an F-type star. When the star expands into a red giant, the hot Jupiter's ...
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4 votes
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Why do degenerate objects get hotter as more mass is added?

After reading this question, I decided to post a question about degeneracy. I've seen simulations on large, $15\text{+ }M_J$ objects that are accreting mass. They do not grow in radius, instead they ...
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2 votes
0 answers
83 views

How big can an object get before its core becomes degenerate?

I am wondering, what is the most massive object we know of that does not have a degenerate core, and what is the least massive object that does have a degenerate code? We know that Jupiter has a core ...
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17 votes
3 answers
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Why do massive stars not undergo a helium flash

I understand that for low-mass stars the helium flash occurs due to their degenerate helium cores. Thus the answer to this question is probably that more massive stars do not have a degenerate core, ...
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5 votes
2 answers
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Can the Sun contain degenerate matter?

Degenerate matter (neutronium) is hypothesized to be very dense and, at a certain amount, unstable - in the sense of collapsing on itself and causing fusion. The result would be a massive fusion ...
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3 votes
2 answers
155 views

Electron Degeneracy Pressure

The Z/A term for calculations of degeneracy pressure for white dwarfs is given as 0.5. But I can't find an explanation as to why. For my assignment, I am trying to find the degeneracy pressure for the ...
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2 votes
2 answers
153 views

If Jupiter were to absorb all other planets in the solar system, would it reach degeneracy pressure?

Jupiter's mass is about the maximum a planet can be before it starts to fuse hydrogen in its core and undergo a massive transformation. Total mass of all solar system objects in question is: here. ...
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6 votes
2 answers
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Measures for the degeneracy from protons?

Come to think of it, the only things we hear about degeneracy is neutron and electron. I made a generalization: White Dwarf: Supported by electron degeneracy. Neutron Star: Supported by neutron ...
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2 votes
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Smallest mass of star to be a black hole? [duplicate]

It seems to me that I forgot the smallest mass of a star and its angular momentum in order to form a black hole. So I know that electron degeneracy pressure is overcome if the core is 1.4 solar ...
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1 vote
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White Dwarf/Degenerate Gas Behaviour

just want to try to clarify a few things about the nature of White Dwarfs and degenerate gases. So if a white dwarf is help up by an electron degenerate gas, the electrons are unable to lose energy ...
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6 votes
1 answer
108 views

Can the Dark Energy be Pauli pressure?

Some neutrinos are fermions. There are quite of few of them out there. Could their degeneracy pressure give rise to an expansion force to explain Dark Energy?
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2 votes
1 answer
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Central temperature of a stellar model with combination of gas and degeneracy

If we have a stellar density model $\rho(r) = \rho_c(1-r/R)$, where the star is composed of ions behaving as perfect gas and electron with non-relativistic degeneracy. The central pressure is due to ...
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0 votes
1 answer
426 views

What is the condition for the number density of a gas to be ultra-relativistic or non-relativistic and degenerate or ideal

What is the condition for the number density ($n$) of a gas to be ultra-relativistic or non-relativistic and degenerate or ideal? I found problems in this subject when I was reading about White-...
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6 votes
1 answer
950 views

White Dwarf and Degenerate Matter

How do we know degenerate matter exists on white dwarfs? Is it purely hypothetical or have we observed it before? Have we ever created a form of degenerate matter on earth?
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3 votes
1 answer
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Are gas giants supported by thermal pressure?

I've heard gas giants are supported because there is an equilibrium between thermal pressure and gravity. That is, if Jupiter were to suddenly begin compressing, temperatures would increase to the ...
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2 votes
1 answer
213 views

How massive can a cold solid object be?

I understand that a neutron star is dense enough that adding more matter will increase the amount of degenerate matter directly, and the limit to its size is about 1.4 solar masses. But if an object ...
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8 votes
2 answers
1k views

Are white dwarf stars supported by proton degeneracy as well?

In general, fermions form a degenerate gas under high density or extremely low temperature. It's clear that white dwarf stars are supported by electron degeneracy pressure. However, there are still a ...
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6 votes
2 answers
2k views

Why is the core of a gas giant supported by electron degeneracy pressure instead of nuclear fusion?

After a Sun-sized protostar forms, its core will become denser over time due to radiation. The core eventually gets dense and hot enough for hydrogen fusion to take place. In the late phases of the ...
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2 votes
2 answers
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What would happen to a gas planet if its core mass goes beyond the Chandrasekhar limit?

Hypothetically, let's say we had a gas giant that continued to accrete mass. I've heard that the cores of gas giants are electron degenerate. So if the planet continued to accrete mass and the core ...
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3 votes
1 answer
2k views

Why can't neutron stars ignite and explode?

Beyond the Chandrasekhar limit, white dwarfs become extremely hot. As a result, previously unfusable carbon can become fusable, causing nuclear reactions. This leads to a thermal runaway and ...
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6 votes
2 answers
973 views

Why does the Chandrasekhar limit affect white dwarfs differently?

The Chandrasekhar limit is the maximum mass of a stable white dwarf star. Beyond this, a carbon-oxygen white dwarf will typically explode in a type 1a supernova, due to the nuclear reactions at those ...
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6 votes
4 answers
2k views

How could a neutron star collapse into a black hole?

White dwarfs usually do not collapse, as they have electron degeneracy pressure due to the Pauli exclusion principle. However, if one accretes mass beyond the Chandrasekhar limit, it is energetically ...
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2 votes
2 answers
1k views

Electron Degeneracy Pressure and the Pauli Exclusion Principle

I have read that what keeps white dwarfs from gravitational collapse is electron degeneracy pressure. How does this pressure prevent further collapse, and how is it related to the Pauli Exclusion ...
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