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A quark star or strange star is a hypothetical type of exotic star composed of quark matter, or strange matter. An exotic star is a Compact star composed of something other than Electrons Protons and Neutrons balanced against Gravitational collapse Quark matter or QCD matter (see QCD) refers to any of a number of theorized phases of matter whose degrees of freedom include Quarks and Gluons For the physics concept see Strange matter. Strange Matter is a Children's book series created by Marty M These are ultra-dense phases of degenerate matter theorized to form inside particularly massive neutron stars. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties Degenerate matter is matter which has sufficiently high Density that the dominant contribution to its Pressure rises from the Pauli Exclusion A neutron star is a type of remnant that can result from the Gravitational collapse of a massive Star during a Type II, Type Ib or Type

It is theorized that when the neutron-degenerate matter which makes up a neutron star is put under sufficient pressure due to the star's gravity, the individual neutrons break down into their constituent quarks, up quarks and down quarks. Degenerate matter is matter which has sufficiently high Density that the dominant contribution to its Pressure rises from the Pauli Exclusion Gravitation is a natural Phenomenon by which objects with Mass attract one another This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. In Physics, a quark (kwɔrk kwɑːk or kwɑːrk is a type of Subatomic particle. The up quark is a particle described by the Standard Model theory of Physics. The down quark is a first-generation Quark with a charge of -(1/3 e. Some of these quarks may then become strange quarks and form strange matter. The strange quark is a second- generation Quark with a charge of &minus(1/3 e and a strangeness of &minus1 The star then becomes known as a "quark star" or "strange star", similar to a single gigantic hadron (but bound by gravity rather than the strong force). In Particle physics, a hadron ( from the ἁδρός hadrós, " stout, thick " ( In particle physics the strong interaction, or strong force, or color force, holds Quarks and Gluons together to form Protons and Quark matter/strange matter is one candidate for the theoretical dark matter that is a feature of several cosmological theories. In Physics and cosmology, dark matter is hypothetical Matter that does not interact with the electromagnetic force but whose presence can be inferred from Physical cosmology, as a branch of Astronomy, is the study of the large-scale structure of the Universe and is concerned with fundamental questions about its

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Quark star

A quark star may be formed from a neutron star through a process called quark deconfinement. A neutron star is a type of remnant that can result from the Gravitational collapse of a massive Star during a Type II, Type Ib or Type In Physics, a quark (kwɔrk kwɑːk or kwɑːrk is a type of Subatomic particle. Deconfinement in Quantum chromodynamics refers to a Phase of matter in which Quarks and Gluons are free to move over distances larger than a This process may produce a quark nova. A quark-nova is a hypothetical type of Supernova that could occur if a Neutron star spontaneously collapsed to become a Quark star. The resultant star should have free quarks in its interior. The deconfinement process should release immense amounts of energy, perhaps being the most energetic explosions in existence. It may be that gamma ray bursts are indeed quark-novae. Gamma-ray bursts ( GRB s are the most luminous electromagnetic events occurring in the Universe since the Big Bang. A quark star lies between neutron stars and black holes in terms of both mass and density, and if sufficient additional matter is added to a quark star, it will collapse into a black hole. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e

Neutron stars with masses of 1. 5–1. 8 solar masses with rapid spin are theoretically the best candidates for conversion. This amounts to 1% of the projected neutron star population. An extrapolation based on this indicates that up to 2 quark-novae may occur in the observable universe each day.

Theoretically quark stars may be radio quiet, so radio-quiet neutron stars may be quark stars. A radio-quiet neutron star is a Neutron star that does not seem to emit radio emissions like most other neutron stars.

Strange star

Recent theoretical research has found mechanisms by which quark stars with "strange quark nuggets" may decrease the objects' electric fields and densities from previous theoretical expectations, causing such stars to appear very much like—nearly indistinguishable from—neutron stars [1]. A strangelet is a hypothetical object consisting of a bound state of roughly equal numbers of up, down, and strange Quarks The size would be However, the team made some fundamental assumptions that led to uncertainties in their theory large enough that the case for it is not yet solid. More research, both observational and theoretical, remains to be done on strange stars in the future.

Other theoretical work [2] contends that, "A sharp interface between quark matter and the vacuum would have very different properties from the surface of a neutron star"; and, addressing key parameters like surface tension and electrical forces that were neglected in the original study, the results show that as long as the surface tension is below a low critical value, the large strangelets are indeed unstable to fragmentation and strange stars naturally come with complex strangelet crusts, analogous to those of neutron stars. For the work of fiction see Surface Tension (short story. Surface tension is a property of the surface of a Liquid that causes it to In Physics, the space surrounding an Electric charge or in the presence of a time-varying Magnetic field has a property called an electric field (that can A strangelet is a hypothetical object consisting of a bound state of roughly equal numbers of up, down, and strange Quarks The size would be

Other theorized quark formations

Observed overdense neutron stars

Quark stars and strange stars are largely theoretical at this point, but observations released by the Chandra X-Ray Observatory on April 10, 2002 detected two candidates, designated RX J1856.5-3754 and 3C58, which had previously been thought to be neutron stars. The Chandra X-ray Observatory is a Satellite launched on STS-93 by NASA on July 23, 1999. Events 879 - Louis III becomes King of the Western Franks. 1407 - the lama See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. RX J18565-3754 (also called RX J185635-3754, RX J185635-375, and various other designations is a nearby Neutron star. 3C58 (aka 3C 58) is a Pulsar and surrounding synchrotron nebula within the Milky Way that is possibly associated with the Supernova Based on the known laws of physics, the former appeared much smaller and the latter much colder than it should be, suggesting that they are composed of material denser than neutron-degenerate matter. Degenerate matter is matter which has sufficiently high Density that the dominant contribution to its Pressure rises from the Pauli Exclusion However, these observations have been under attack by researchers who say the results were not conclusive; it remains to be seen how the question of quark star or strange star existence will play out. Recently a third star, XTE J1739-285, [3] has been observed by a team led by Philip Kaaret of the University of Iowa, and also reported as a possible candidate. |- style="vertical-align top"| Distance | 39000 Ly XTE J1739-285 is a Neutron star, or possibly a Strange star. The University of Iowa, is a major teaching service and Research university located on a campus in Iowa City Iowa, on the banks of the Iowa River

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External links

References

  1. ^ P. Jaikumar, S. Reddy, A. Steiner, "The Strange Star Surface: A Crust with Nuggets", Phys. Rev. Lett. 96 041101 (2006) arXiv:nucl-th/0507055
  2. ^ M. Alford, K. Rajagopal, S. Reddy, A. Steiner, "The Stability of Strange Star Crusts and Strangelets", Phys. Rev. D73 114016 (2006) arXiv:hep-ph/0604134
  3. ^ Fastest spinning star may have exotic heart - space - 20 February 2007 - New Scientist Space
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