Экзотикалық жұлдыздар: Гипотетикалық тығыз материялар

Hypothetical compact star made of exotic matter

An exotic star is a hypothetical compact star composed of exotic matter (something not made of electrons, protons, neutrons, or muons), and balanced against gravitational collapse by degeneracy pressure or other quantum properties. Types of exotic stars include
quark stars (composed of quarks)
strange stars (composed of strange quark matter, a condensate of up, down, and strange quarks)
s (speculative material composed of preons, which are hypothetical particles and "building blocks" of quarks and leptons, should quarks be decomposable into component sub particles). Of the various types of exotic star proposed, the most well evidenced and understood is the quark star, although its existence is not confirmed. In Newtonian mechanics, objects dense enough to trap any emitted light are called dark stars,efn|
Quantum effects may prevent true black holes from forming and give rise instead to dense entities called black stars.

An electroweak star is a hypothetical type of exotic star in which the gravitational collapse of the star is prevented by radiation pressure resulting from electroweak burning; that is, the energy released by the conversion of quarks into leptons through the electroweak force. This process occurs in a volume at the star's core approximately the size of an apple and containing about two Earth masses. The stage of life of a star that produces an electroweak star is theorized to occur after a supernova collapse. Electroweak stars are denser than quark stars, and may form when gravitational attraction can no longer be withstood by quark degeneracy pressure, but can still be withstood by electroweak burning radiation pressure. This phase of a star's life may last upwards of 10 million years.

A preon star is a proposed type of compact star made of preons, a group of hypothetical subatomic particles. Preon stars would be expected to have huge densities, exceeding  kg/m3. They may have greater densities than quark stars, and they would be heavier but smaller than white dwarfs and neutron stars. Preon stars could originate from supernova explosions or the Big Bang. Such objects could be detected in principle through gravitational lensing of gamma rays. Preon stars are a potential candidate for dark matter. However, current observations from particle accelerators speak against the existence of preons, or at least do not prioritize their investigation, since the only particle detector presently able to explore very high energies (the Large Hadron Collider) is not designed specifically for this and its research program is directed towards other areas, such as studying the Higgs boson, quark–gluon plasma and evidence related to physics beyond the Standard Model.

In loop quantum gravity, a Planck star is a hypothetically possible astronomical object that is created when the energy density of a collapsing star reaches the Planck energy density. Under these conditions, assuming gravity and spacetime are quantized, there arises a repulsive "force" derived from Heisenberg's uncertainty principle. In other words, if gravity and spacetime are quantized, the accumulation of mass energy inside the Planck star cannot collapse beyond this limit to form a gravitational singularity because it would violate the uncertainty principle for spacetime itself.

Q stars are hypothetical objects that originate from supernovae or the big bang. They are theorized to be massive enough to bend space time to a degree such that some, but not all light could escape from its surface. These are predicted to be denser than neutron stars or even quark stars.