gravitational collapse

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gravitational collapse:

see black holeblack hole,
in astronomy, celestial object of such extremely intense gravity that it attracts everything near it and in some instances prevents everything, including light, from escaping.
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The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.

gravitational collapse

Contraction of a body arising from the mutual gravitational pull of all its constituents. Although there are several examples of such contraction processes in astronomy, ‘gravitational collapse’ usually refers to the sudden collapse of the core of a massive star at the end of nuclear burning, when its internal gas pressure can no longer support its weight. For a massive star this may initially result in a supernova explosion, removing much of the star's mass. The eventual degree of gravitational collapse is determined by the mass that remains after a supernova, or after any other form of mass loss. The three most likely end-products (in order of increasing mass) are white dwarfs, neutron stars, and black holes.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Gravitational Collapse


(in astronomy), the catastrophically rapid compression of a star under the action of gravitational attraction.

According to existing astronomical conceptions, gravitational collapse plays a decisive role in the late stages of the evolution of massive stars. During the billions of years of its prior existence, a star is in equilibrium: the forces of gravitational attraction, which tend to compress the star’s material, are balanced by the forces of hot gas pressure, which counteract compression. Thermonuclear reactions proceeding in the star’s central regions at temperatures of tens of millions of degrees are the sources of the star’s radiant energy. After several billion years, the star’s nuclear sources of energy are exhausted. Meanwhile, the star continues to lose energy, radiating light into space from its surface and neutrinos from its interior. This leads to a very slow contraction of the star’s central regions. If the star’s mass is not less than 1.2 solar masses, then the density and pressure in the star’s central regions increase so much that nuclear reactions begin to occur involving the breakdown of complex nuclei, during which an enormous amount of heat is absorbed. This leads to the following: with the increase in the density of the gas the forces of hot gas pressure do not rise as fast as the gravitational forces, the equilibrium between these forces is upset, and under the influence of gravity, now not balanced by the force of gas pressure, the star tends to contract—gravitational collapse occurs.

The process takes a fraction of a second, but in this time the density of the central parts of the star increases to that of the atomic nucleus, about 1014 g/cm3. Now the already powerful repulsive forces of the nuclear particles pressing on each other slow or even halt the compression of matter in the star’s central regions. The falling outer layers of the star encounter the layers that have come to rest, and an outward-traveling shock wave is generated, which is reinforced by neutrinos emanating from the interior and by the detonation of the remnants of the nuclear “fuel” in the star’s envelope. The star’s outer layers are ejected into space. This ejection process is observed as the explosions of supernovas. The core remaining after the ejection of the envelope of a star with a mass not exceeding 2 solar masses is a neutron star. Astronomers observe such stars as sources of pulsating radio emission—pulsars.

If the mass of the star’s core is large (greater than 2 solar masses), then the repulsion of the nuclear particles is not able to withstand the gravity, and the star’s core, after rapid cooling, will continue to contract. In this case, its gravitational field increases so much that the effects of the general theory of relativity begin to play a role, and no force can any longer halt the contraction. This stage of a star’s evolution is called relativistic gravitational collapse. When the star’s radius becomes equal to a critical value (determined by the star’s mass and equal to 3 M0 km, where M0 is the star’s mass expressed in solar masses), the gravitational field no longer releases radiation or particles. Such a celestial object is called a black hole or frozen star.


Zel’dovich, Ia. B., and I. D. Novikov. Teoríia tiagoteniia i evoliutsiia zvezd. Moscow, 1971.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

gravitational collapse

[‚grav·ə′tā·shən·əl kə′laps]
The implosion of a star or other astronomical body from an initial size to a size hundreds or thousands of times smaller.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
They do not arise from gravitational collapse. The only feasible solution is that they are the result of condensation reactions, whereby material, as it condenses and forms a new system, emits photons into its surroundings.
It is believed that this extension is not crustal extension but is rather gravitational collapse recording the crustal uplift resulting from salt intrusion.
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Banerjee, "Non-adiabatic gravitational collapse in higher dimensional space-time and its junctions conditions," Astrophysics and Space Science, vol.
thus we find that the problem of Jeans gravitational instability is the important phenomena to understand gravitational collapse of the protostar.
By continuing to study the gravitational collapse of a sphere of dust in isotropic coordinates, and by applying the current research to other types of black holes, views where the universe is born from the interior of an Einstein-Rosen black hole could avoid problems seen by scientists with the Big Bang theory and the black hole information loss dilemma, which claims all information is lost as it goes over the event horizon (in turn defying the laws of quantum physics).
Gomez R, Winicour J (1992) Asymptotics of gravitational collapse of scalar waves.
Under some conditions, the aftermath is actually visible, and he draws on the general theory of relativity to explain how these visible ultra-dense regions arise naturally and generically as the outcome of a dynamical gravitational collapse in Einstein gravity.
"Gravity conserves entropy; for example, in the cosmic gravitational collapse of the "Big Crunch", the total heat loss and entropy of the Universe is reversed; in such a case, the total entropy of the Universe sums to zero.
The fifth, "Black Holes and Beyond," discusses the enigmatic objects that result from a star's catastrophic gravitational collapse. The final program, "An Answer to Everything," examines scientists' attempts to develop a complete theory of how the universe works.
(iii) Schwarzschild gravitational collapse black hole singularities (iv) Schwarzschild vacuum black hole singularities, (v) Reissner-Nordstrom gravitational collapse black hole singularities, (vi) Reissner-Nordstrom vacuum black hole singularities (vii) Kerr gravitational collapse black hole singularities, and (viii) Kerr vacuum black hole singularities.
But if a quasar is on its inexorable way to becoming a black hole--or "collapsar" as Campbell put it--all the interstellar matter and star stuff surrounding this gravitational collapse would be screaming in cosmic agony throughout the electromagnetic spectrum while being sucked into this ineffable vortex.