Could a Star Collapse into a Quark Star Instead of a Black Hole?

[AbsoluteZer0]

Hi,

In the case of the gravitational collapse of a star where neither electron or neutron degeneracy pressure is sufficient to prevent further collapse, is there a possibility that the star will become a quark star rather than a black hole?

From what I understand, quarks are perpetually bound to each other by color confinement, so would this prevent a quark star from being possible?

Thanks,

 

[mathman]

Whether or not a star ends up as a black hole depends only on its radius and mass. What its composition is doesn't matter. So if a neutron star collapsed to be a quark star (I am not sure what it means physically), it will be a black hole if the radius is small enough.

 

[Chronos]

A quark star is hypothetically the last stop on the road to becoming a black hole. Their existence is still conjecture, although some promising candidates exist - e.g., http://arxiv.org/abs/astro-ph/0204159 and http://arxiv.org/abs/astro-ph/0204151. Unfortunately our knowledge of the equation of state of quark matter is virtually nonexistent. Even our knowledge of neutron star EOS is extremely poor and we can only guess at the states of matter that exist beneath their surfaces. A quark star could be dense enough to exceed the schwarzschild limit making it a black hole without a singularity. Needless to say this is an active area of research. We still have much to learn about condensed matter.

 

[twofish-quant]

In the case of the gravitational collapse of a star where neither electron or neutron degeneracy pressure is sufficient to prevent further collapse, is there a possibility that the star will become a quark star rather than a black hole?

Not really in the sense of a "neutron star". The trouble is that quarks are less massive than neutrons, which means that if the neutrons are relativistic then the quarks are even more relativistic.

Now it's possible (even likely) that the interior of a "neutron star" is actually not made of neutrons but of "quark soup". This matters because if particles start behaving like quarks rather than neutrons, the mass at which black holes form decreases a lot.

The difference is that when you put enough matter into a white dwarf, it suddenly changes into a neutron star. With neutron stars, the current thinking is that as you pile on matter, the center gradually behaves more and more like free quarks, so there isn't a sharp transition between a neutron star and a quark star.

 

[pmacias]

I can say that the formation of quark stars is a fascinating and ongoing area of research in astrophysics. While black holes are a common outcome of gravitational collapse, there is indeed a possibility that a star could become a quark star instead.

Quark stars are hypothetical objects composed entirely of quarks, the fundamental building blocks of matter. These quarks are held together by the strong nuclear force, which is stronger than the force of gravity. The idea of quark stars was first proposed in the 1980s as a possible alternative to black holes.

However, as you mentioned, quarks are bound by color confinement, which means they cannot exist in isolation and are always found in composite particles such as protons and neutrons. This raises the question of whether a quark star could actually exist, as the quarks would be confined within the star's interior.

Recent studies have suggested that under extreme conditions, such as the high temperatures and pressures found in the core of a collapsing star, quarks may be able to break free from their confinement and form a new state of matter known as a quark-gluon plasma. This could potentially allow for the existence of quark stars.

But the formation of quark stars is still a subject of ongoing research and debate. More studies and observations are needed to fully understand the conditions under which quark stars could form and whether they could actually exist in our universe.

In summary, while the concept of quark stars is intriguing, there is still much to be discovered and understood about their formation and existence. It is an exciting area of study that continues to push the boundaries of our understanding of the universe.