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Q Star
A Q-star, also known as a grey hole, is a hypothetical type of compact, heavy neutron star with an exotic state of matter. Such a star can be smaller than the progenitor star's Schwarzschild radius and have a gravitational pull so strong that some light, but not all photons, can escape. The Q stands for a conserved particle number. A Q-star may be mistaken for a stellar black hole.* Types of Q-stars * Q-ball *B-ball, stable Q-balls with a large baryon number B. They may exist in neutron stars that have absorbed Q-ball(s). See also *Black hole **Stellar black hole *Compact star ** Exotic star *** Boson star *** Electroweak star *** Preon star ***Strange star A strange star, also called a strange quark star, is a hypothetical compact astronomical object, a quark star made of strange quark matter. Strange stars might exist without regard to the Bodmer–Witten assumption of stability at near-zero te ... *** Quark star References Further reading * Degenerate stars Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exotic Matter
There are several proposed types of exotic matter: * Hypothetical particles and states of matter that have not yet been encountered, but whose properties would be within the realm of mainstream physics if found to exist. * Several particles whose existence has been experimentally confirmed that are conjectured to be exotic hadrons and within the Standard Model. * State of matter, States of matter that are not commonly encountered, such as Bose–Einstein condensates, fermionic condensates, nuclear matter, quantum spin liquid, string-net liquid, supercritical fluid, color-glass condensate, quark–gluon plasma, Rydberg matter, Rydberg polaron, photonic matter, Wigner crystal, Superfluidity, Superfluid and time crystal but whose properties are entirely within the realm of mainstream physics. * Forms of matter that are poorly understood, such as dark matter and mirror matter. * Ordinary matter that when placed under high pressure, may result in dramatic changes in its physical or c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwarzschild Radius
The Schwarzschild radius is a parameter in the Schwarzschild solution to Einstein's field equations that corresponds to the radius of a sphere in flat space that has the same surface area as that of the event horizon of a Schwarzschild black hole of a given mass. It is a characteristic quantity that may be associated with any quantity of mass. The Schwarzschild radius was named after the German astronomer Karl Schwarzschild, who calculated this solution for the theory of general relativity in 1916. The Schwarzschild radius is given as r_\text = \frac , where ''G'' is the Newtonian constant of gravitation, ''M'' is the mass of the object, and ''c'' is the speed of light. History In 1916, Karl Schwarzschild obtained an exact solution to the Einstein field equations for the gravitational field outside a non-rotating, spherically symmetric body with mass M (see ''Schwarzschild metric''). The solution contained terms of the form and , which have Mathematical singularity, singula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Black Hole
A stellar black hole (or stellar-mass black hole) is a black hole formed by the gravitational collapse of a star. They have masses ranging from about 5 to several tens of solar masses. They are the remnants of supernova explosions, which may be observed as a type of gamma ray burst. These black holes are also referred to as collapsars. Properties By the no-hair theorem, a black hole can only have three fundamental properties: mass, electric charge, and angular momentum. The angular momentum of a stellar black hole is due to the conservation of angular momentum of the star or objects that produced it. The gravitational collapse of a star is a natural process that can produce a black hole. It is inevitable at the end of the life of a massive star when all stellar energy sources are exhausted. If the mass of the collapsing part of the star is below the TOV limit, Tolman–Oppenheimer–Volkoff (TOV) limit for Degenerate matter#Neutron degeneracy, neutron-degenerate matter, the end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-ball
In theoretical physics, Q-ball is a type of non-topological soliton. A soliton is a localized field configuration that is stable—it cannot spread out and dissipate. In the case of a non-topological soliton, the stability is guaranteed by a conserved charge: the soliton has lower energy per unit charge than any other configuration (in physics, charge is often represented by the letter "Q", and the soliton is spherically symmetric, hence the name). Intuitive explanation A Q-ball arises in a theory of bosonic particles when there is an attraction between the particles. Loosely speaking, the Q-ball is a finite-sized "blob" containing a large number of particles. The blob is stable against fission into smaller blobs and against "evaporation" via emission of individual particles, because, due to the attractive interaction, the blob is the lowest-energy configuration of that number of particles. (This is analogous to the fact that nickel-62 is the most stable nucleus because it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Stars
A neutron star is the gravitationally collapsed core of a massive supergiant star. It results from the supernova explosion of a massive star—combined with gravitational collapse—that compresses the core past white dwarf star density to that of atomic nuclei. Surpassed only by black holes, neutron stars are the second smallest and densest known class of stellar objects. Neutron stars have a radius on the order of and a mass of about . Stars that collapse into neutron stars have a total mass of between 10 and 25 solar masses (), or possibly more for those that are especially rich in elements heavier than hydrogen and helium. Once formed, neutron stars no longer actively generate heat and cool over time, but they may still evolve further through collisions or accretion. Most of the basic models for these objects imply that they are composed almost entirely of neutrons, as the extreme pressure causes the electrons and protons present in normal matter to combine into additi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole
A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. The boundary (topology), boundary of no escape is called the event horizon. A black hole has a great effect on the fate and circumstances of an object crossing it, but has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with thermal radiation, the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the Orders of magnitude (temperature), order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Objects whose gravitational fields are too strong for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Black Hole
A stellar black hole (or stellar-mass black hole) is a black hole formed by the gravitational collapse of a star. They have masses ranging from about 5 to several tens of solar masses. They are the remnants of supernova explosions, which may be observed as a type of gamma ray burst. These black holes are also referred to as collapsars. Properties By the no-hair theorem, a black hole can only have three fundamental properties: mass, electric charge, and angular momentum. The angular momentum of a stellar black hole is due to the conservation of angular momentum of the star or objects that produced it. The gravitational collapse of a star is a natural process that can produce a black hole. It is inevitable at the end of the life of a massive star when all stellar energy sources are exhausted. If the mass of the collapsing part of the star is below the TOV limit, Tolman–Oppenheimer–Volkoff (TOV) limit for Degenerate matter#Neutron degeneracy, neutron-degenerate matter, the end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Star
In astronomy, the term compact object (or compact star) refers collectively to white dwarfs, neutron stars, and black holes. It could also include exotic stars if such hypothetical, dense bodies are confirmed to exist. All compact objects have a high mass relative to their radius, giving them a very high density, compared to ordinary atomic matter. Compact objects are often the endpoints of stellar evolution and, in this respect, are also called stellar remnants. They can also be called dead stars in public communications. The state and type of a stellar remnant depends primarily on the mass of the star that it formed from. The ambiguous term ''compact object'' is often used when the exact nature of the star is not known, but evidence suggests that it has a very small radius compared to ordinary stars. A compact object that is not a black hole may be called a degenerate star. In June 2020, astronomers reported narrowing down the source of Fast Radio Bursts (FRBs), which may now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exotic Star
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. Quark stars and strange stars A quark star is a hypothesized object that results from the decomposition of neutrons into their constituent up and down quarks under gravitational pressure. It is expected to be smaller and denser than a neutron star, and may sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preon Star
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. Quark stars and strange stars A quark star is a hypothesized object that results from the decomposition of neutrons into their constituent up and down quarks under gravitational pressure. It is expected to be smaller and denser than a neutron star, and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
