how a star is able to resist collapsing under its own gravitaional attraction?
453834
Pressure from the electromagnetic radiation streaming out of the star.\n\nIIRC, every star is at some equilibrium between gravitational collapse and flying apart due to heat/pressure in the interior generated by the fusion process.  When the fuel being burned in the fusion process is depleted, the star begins to collapse until the resulting pressure ignites the next fuel stage.
142200
The density of it causes it to have more mass, making it have more gravity, meaning it attracts to itself more than anything else on earth pulling it to the center.\n\nMore mass = more gravity.\n\nGravity pulls two objects together. We don't see this because things we see it's too small to notice, but say the earth is attracted to the sun and that's what keeps us in orbit, a black hole is made up of material that is VERY dense and that's why it pulls everything in so strongly, so strong even light doesn't escape. \n\nSo the densest layer of a planet is in the center, and the least dense is on the outer, unless another scientific principle outwieghs that one in application.\n\nImagine a block of iron and a bag of dirt, which would you feel pulling toward the earth stronger?\nYou would percieve the block of iron going toward the surface of the earth stronger than a bag of dirt, but if you think about it it's also moving toward the center of the earth. So that's what happens, the metal is in the middle and the dirt is on the surface.
649714
lots of gravity,  bends anything.
628731
black hole \n\nIn astronomy, celestial object of such extremely intense gravity that it attracts everything near it and in some instances prevents everything, including light, from escaping. The term was first used in reference to a star in the last phases of gravitational collapse (the final stage in the life history of certain stars; see stellar evolution) by the American physicist John A. Wheeler. \n\nGravitational collapse begins when a star has depleted its steady sources of nuclear energy and can no longer produce the expansive force, a result of normal gas pressure, that supports the star against the compressive force of its own gravitation. As the star shrinks in size (and increases in density), it may assume one of several forms depending upon its mass. A less massive star may become a white dwarf, while a more massive one would become a supernova. If the mass is less than three times that of the sun, it will then form a neutron star. However, if the final mass of the remaining stellar core is more than three solar masses, as shown by the American physicists J. Robert Oppenheimer and Hartland S. Snyder in 1939, nothing remains to prevent the star from collapsing without limit to an indefinitely small size and infinitely large density, a point called the "singularity."
111814
The galaxy is help up by angular momentum. The star are all rotating around the center of the galaxy, although the details are different from a simple solar system, and the resulting orbits can be a tad odd.\n\nThe real question is what hold the galaxy together - and that is gravity. Gravity from all the stars, dust, and the massive black home in the center of most galaxies (including ours) and a large gravitational contribution from "missing matter."
600386
You don't need a black hole to be able hold itself together through gravity. Just look at the earth or the moon for example. They are nowhere near as dense as a black hole, yet they support themselves gravitationally.
136826
I am not quite sure what your asking.\n\nWhen the star is forming, it starts out as a gigantic cloud of mostly Hydrogen. As the stellar material coalesces, the material begins to heat up and the pressure at the center of what will become the new star increases dramatically.  The material becomes denser and is pulled together by its own gravity, heating up as the pressure rises.  Gravity is working to pull the star together, and eventually the ball of gas becomes so massive, that the pressure and heat at its core are sufficient to undergo nuclear fusion.  In order to counteract the force of gravity, the Hydrogen at the stars core undergoes fusion, in the process, producing Helium and a lot of energy.  It is this energy produced from nuclear fusion at the stars core that keeps the star from collapsing in on itself.
170908
There are two forces involved to keep a satellite from falling down. First, GRAVITY is constantly trying to pull the satellite down, but at the same time the satellite's speed is trying to hurl it off into space--CENTRIPETAL force. As long as both forces are exactly balanced, the satellite won't fall down.
732762
Their materials collect together (via gravity) and make new stars.  Granted, they tend to be made of heavier materials and burn cooler (often red).\n\nStars collapse when they run out of material.  A star begins by fusing hydrogen into helium.  Eventually, the hydrogen runs out and the star begins to collapse until it is able to fuse helium into carbon.  This continues through various elements until it is largely iron.  A star is simply not able to fuse iron into anything else (their not massive enough), so it eventually has a final collapse, sometimes into a supernova.\n\nThis final collapse can leave three possible "leftovers":\n1.  A white dwarf - if the star is less than 3 x the mass of our sun, then the core will be left as a burning ember.  Eventually it will burn out to become something known as a brown dwarf, a dead star.\n\n2.  A neutron star - if the star is between 3 and 10 (I think) x the mass of our sun, the explosion compresses the core down enough that protons and electrons are crammed together to form a neutron star.  It's a bunch of neutrons so dense a teaspoonful would weigh, well, tons on the earth.\n\n3.  A black hole - if the star is especially massive, the collapse never ends.  The core itself cannot overcome the massive gravity that is created by a now extremely dense remnant, forming a black hole.
1021091
Self gravitation is thought to have been the main cause of the collapse of the solar nebula.  \n\nIn addition, there is some evidence (from isotopic analyses of primitive meteorites) for the addition to the nebula of elements that were produced by nucleosynthesis in a supernova "shortly" before the aggregation of  nebular material into macroscopic solid bodies.  A pressure wave associated with the arrival of this supernova material may have been triggered or accelerated the collapse.  More recent research, however, suggests that at least some of the isotopic anomalies that gave rise to this idea may have been produced by irradiation of solar nebular material by the sun itself, rather than from an extrasolar event.
279317
gravity.\n\nany shape of mass that is not spherical is gravitationally unstable
593845
Great Question\nBlack hole fast facts:\n\n1.Once a large star dies, its internal gravitational strength causes all of the stars matter to collapse in on itself,(electrons are compressed into and combined with the atoms nucleus), this forms a neutron star.\nA neutron star, if dense enough will continue to collapse inward compressing the neutron matter further until it exists as matter/energy in its purest form. (All matter and energy is coalesced into one single state of energy)\n\n2.They are the single largest gravitational entity theorized to exist. This large gravitational attraction pulls in matter (atoms) and adds it to the singularity (energy mass) at its center.\n\n3.They represent the possible end of our universe.(big crunch)\n\n4.They are one of the few places that prohibit the propagation of light.\n\n5.The laws of nature at a black hole are completely different from anywhere else in the universe.\n\nThese are the main highlights.
330944
A black hole is a very large star, many times more massive than our Sun, that has collapsed under its own gravity (Usually, the star doesnt collapse because the nuclear reactions occuring in its core counter the gravitational force) The gravitational field around a black hole is so strong that not even light can escape
511957
When a star die, it may become a white dwarf or cause a supernova explosion according to there masses.If a star is more than chandra limit (1.44times the sun mass)the outer envelope increases in size due to loss of energy.the inner core still shrinks under the imbalanced force of gravity.the force increases to such an effect that the electrons are also sucked in the nucleus and the star is now composed of protons only.hence it emits radio waves called pulsar and the star is called a neutron star.
952509
The sun balances it's tendancy to gravitationally collapse with radiation pressure.  Once nuclear fusion stops, the radiation pressure won't be able to stop the sun from collapsing anymore.
80
Largely because of the massive amounts of gravitational force involved.  A sphere is the only sustainable shape when talking about forces of that magnitude.  Stars are incredibly dense towards their core, and over billions of years the matter will coalesce in a sphere like shape.
1152122
A star is a big mass of gas. It originated as a hydrogen cloud  that started contracting because gravity pulled it together. When this happens the interior gets denser and hotter. Dense enough and hot enough for fusion reactions to start. The latter produce heat and light that pushes outwards.\n\nThe result is an equilibrium between gravity and the light radiation. The star stabilizes and stays stable for billions of years. The sun is in this stage.\n\nHowever, when the hydrogen is burnt up, the outward pressure is taken away and gravity takes over again. If the mass of this burnt out star is big enough, then there is nothing to counteract gravity.\n\nThe mass of the star will be more and more concentrated in a smaller and small volume. Gravity at the surface will become so strong that not even light can escape from it. \n\nThat is a black hole.