Do globular clusters contain massive black holes?
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I think so if I'm not right you should go to kidsastronomy.com it helped me on science hw
13556
There are theoretically two ways in which black holes can form.  Stellar (star) sized black holes have to be above the Chandresekhar limit of 3.2 solar masses, and are formed through the gravitational collapse of stars. They can form whenever conditions are right. These are the types of black holes that astronomers infer from binary X-ray sources and the like.\n\nMicro black holes, on the other hand, can only have been formed in the initial moments of the Big Bang, when intense pressures during cosmic expansion could have collapsed masses smaller than our sun into singularities.  According to Dr. Stephen Hawking's theory of black hole evaporation, all singularities lose mass, through a type of evaporation (the actual mechanism, having to do with vaccum energy and particle/antiparticle pairs is a bit complicated) with smaller black holes evaporating faster than large ones.  By this logic, most micro-holes would have evaporated out of existence in the thirteen billion years the universe has been around, while the larger micro-holes (things with the mass of, say, Neptune) should still be around, though hard to spot.
57666
If two bodies (stars, black holes, anything) get close enough to be gravitationally bound they will develop some sort of orbit in which the two bodies circle each other. \n\n\nEinstein's theory of General Relativity predicts that when two very massive objects(like Black Holes and Neutron Stars) are caught in an orbit like this they will generate Gravitational Waves (Ripples in Space-Time). These Gravitational Waves carry energy away from the orbiting bodies which means that with each successive revolution they get closer to each other. Eventually the orbit gets so small that the two bodies merge. \n\n\nThe merger of two black holes entails a lot of complicated General Relativity and some non-intuitive physics, but theorists use large supercomputers to simulate such events. There are two primary results to these mergers of which we can be sure of: \n\n1. A single, more massive black hole \n\n2. An extremely powerful burst of gravitational waves \n\n\nThere are currently projects like LIGO which will attempt to directly detect the disturbances in space time caused by gravitational waves. They primarily expect to "see" the results of neutron star and black hole binary mergers. \n\n\nThere was also a recent discovery of a black hole merger in a distant galaxy though this was discovered by observing the jet streams caused by the black holes. You should note that those results are still preliminary and unconfirmed.
84045
A black hole is the collapsed stellar remnant of a supernova (a nova is an entirely different phenomena caused by matter falling onto a white dwarf). Depending on how massive the star is either a white dwarf (lightest) a neutron star (heavier) or a black hole (heaviest) form when a star dies.\n\nType II Supernovas are the catastrophic, yet natural, deaths of massive stars. The star has to be 8 times more massive than the sun to cause a supernova. \n\nOnce a star has used up all of its hydrogen in the fusion processes in the core, there is no more pressure to keep the stars core from collapsing under its own weight. Eventually it gets so hot that the helium begins to fuse which again causes pressure that temporarily halts the collapse. In a star like the sun helium fusion is the end. Once the helium is spent the stars core begins collapsing again while its outer layer puffs out into space leaving a white dwarf. \n\nIn a more massive star carbon fusion, which produces neon and manganese, takes over when the helium is spent because its gravity can cause temperature and pressures great enough. When the carbon is gone the core begins collapsing again. This goes on for several stages of contraction with resulting fusion of increasingly heavier elements. \n\nFinally silicon fuse into iron and the core is the size of earth. The temperature is over 3 billion degrees. No more energy can be produced from fusion as iron is too tightly bound in its nuclei. Instead the iron core collapses with a quarter the speed of light. It shrinks in size from the size of earth to a sphere 100 kilometers across in less then one tenth of a second. This produces gravitational energy 100 times greater than the energy the sun has put out during its entire life. This energy is what blows the outer layers of the star apart. In the expanding envelope neutrons are created that slam into other nuclei to form extremely heavy isotopes. As they decay they form elements heavier than iron. \n\nIn the core, denisty is now so great that protons and electrons can no longer exist. Instead they begin to form neutrons. When that process is complete a neutron star, about 10 to 20 km in diameter, is born. \n\nIf the mass of the star is so great that not even the neutrons can keep it from coallapsing further eventually you end up with an objects so dense its escape velocity becomes greater than the speed of light and a black hole is born.
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The current scientific theory holds that black holes are formed when stars of sufficient mass (about 3x the mass of our Sun) reach the end of their life and collapse down into a singularity, which is, in essence, an infinitely small point with a huge amount of gravity - gravity so powerful that not even light can escape it's pull if it gets too close. It is also thought that black holes can be formed from smaller masses if external energy/pressure is exerted to squeeze the mass into a singularity.\nNot sure if there's any direct experimental evidence of creation, but there is evidence that they exist. Cosmologists use several different methods to detect blacks holes, such as by looking for light being bent and/or disappearing as it travels from remote stars towards us, and also by looking for bursts of x-rays that are given off as matter is sucked into the back hole and destroyed.\nFun fact: current evidence and theory suggests that the center of the Milky Way is a giant black hole that was formed as the densly packed stars in the center collapsed and sucked each other in.
345783
Yes, black holes can move in space,\npartially due to the law of conservation of momentum (and inertia), if it was moving before it became a black hole, it will continue to move,\nand a black hole is affected by gravity like other objects.\n\nIt has been theorized, and some experimental evidence confirms, that larger (super-massive) black holes reside within many galaxy's centers.  As we can observe, galaxies can, and do, move around...thus if they have a black hole at thier center, the black hole moves as well.
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We haven't actually had a black hole close enough to experiment with, at least not that we know about--although there are theories about dryers having a black hole that eats socks, see earlier response!!--so most of the work on black holes is done with theory, prediciting what a black hole might do, and then seeing if something out there is doing it.\n\nNow, the best data seems to be based on the orbital velocities of stars in galaxies: the velocity distributions demand a truly massive central mass in a lot of the galaxies, one that is best viewed as a black hole.\n\nSome very nice data exists with observations of events predicted to happen with "near misses" with black holes--particles that get into the titanic gravity well of the black hole, but decay into two particles, one escaping the black hole.\n\nBut no one has actually seen a black hole do anything, directly..
575553
Nope.  Whoever told you this has been watching too much science fiction.\n\nBlack holes are just collapsed stars, and their gravity is no bigger than any other star (except to things that are very close to it).  There are enormous black holes at the center of galaxies, but these don't pose a threat to the majority of the galaxy ... and the earth is way out near the edge of our galaxy.  And there is no black hole even theorized that is big enough to swallow entire galaxies.
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Our Sun's mass isn't great enough to create a black hole, but speaking in a hypothetical situation it would suck everything into including the planets and so forth because its gravitational pull is so great.  However, recent astronomical studies have proven using a spectrometer and examining the data produced by it the stars in almost every single galaxy are moving at a rate which only indicates the presence of a super massive black hole in almost every single galaxy.  The size of the black hole is dependent upon the galaxies size and is directly related to its sigma, but these black holes are present in almost every galaxy we have viewed, including our own and are currently not feeding anymore and are dormant.  They believe that they helped form the galaxy in some way but it is not known yet.  So maybe it is possible if the Sun created a black hole it would feed to the point that it also became dormant, probably not though.
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A black hole is what remains when a massive star dies. \nThe concept of an object from which light could not escape (e.g., black hole) was originally proposed by Pierre Simon Laplace in 1795. Using Newton's Theory of Gravity, Laplace calculated that if an object were compressed into a small enough radius, then the escape velocity of that object would be faster than the speed of light.\nIf you have read How Stars Work, then you know that a star is a huge, amazing fusion reactor. Because stars are so massive and made out of gas, there is an intense gravitational field that is always trying to collapse the star. The fusion reactions happening in the core are like a giant fusion bomb that is trying to explode the star. The balance between the gravitational forces and the explosive forces is what defines the size of the star. \nAs the star dies, the nuclear fusion reactions stop because the fuel for these reactions gets burned up. At the same time, the star's gravity pulls material inward and compresses the core. As the core compresses, it heats up and eventually creates a supernova explosion in which the material and radiation blasts out into space. What remains is the highly compressed, and extremely massive, \ncore. The core's gravity is so strong that even light cannot escape. \nThis object is now a black hole and literally disappears from view. Because the core's gravity is so strong, the core sinks through the fabric of space-time, creating a hole in space-time -- this is why the object is called a black hole. When material falls into a black hole from a companion star, it gets heated to millions of degrees Kelvin and accelerated.The star Cygnus X-1 is a strong X-ray source and is considered to be a good candidate for a black hole. stellar winds from the companion star, HDE 226868, blow material onto the accretion disk surrounding the black hole.As this material falls into the black hole, it emits X-rays.In addition to X-rays, black holes can also eject materials at high speeds to form jets. Many galaxies have been observed with such jets. Currently, it is thought that these galaxies have supermassive black holes (billions of solar masses) at their centers that produce the jets as well as strong radio emissions.One such example is the galaxy M87.It is important to remember that black holes are not cosmic vacuum cleaners -- they will not consume everything. So although we cannot see black holes, there is indirect evidence that they exist. They have been associated with time travel and worm holes and remain fascinating objects in the universe. There are two types of black holes: \nSchwarzschild - Non-rotating black hole \nKerr - Rotating black hole \nThe Schwarzschild black hole is the simplest black hole, in which the core does not rotate. This type of black hole only has a singularity and an event horizon. \nThe Kerr black hole, which is probably the most common form in nature, rotates because the star from which it was formed was rotating. When the rotating star collapses, the core continues to rotate, and this carried over to the black hole (conservation of angular momentum). The Kerr black hole has the following parts: \nSingularity - The collapsed core \nEvent horizon - The opening of the hole \nErgosphere - An egg-shaped region of distorted space around the event horizon (The distortion is caused by the spinning of the black hole, which "drags" the space around it.) \nStatic limit - The boundary between the ergosphere and normal space \nIf an object passes into the ergosphere it can still be ejected from the black hole by gaining energy from the hole's rotation. \nHowever, if an object crosses the event horizon, it will be sucked into the black hole and never escape. What happens inside the black hole is unknown; even our current theories of physics do not apply in the vicinity of a singularity. \nEven though we cannot see a black hole, it does have three properties that can or could be meas
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Black Holes are strongly suspected to be responsible for a few powerful X-ray stars, and also to be at the center of most Galaxies - including ours.\n\nBut, while these are all much to far away for us to get to now - probably ever. You can see what the trip would be like with the Virtual Trips to Black Holes and Neutron Stars web page:\nhttp://antwrp.gsfc.nasa.gov/htmltest/rjn_bht.html\nand with the animations on the Falling into a Black Hole page:\nhttp://casa.colorado.edu/~ajsh/schw.shtml
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no, but i can tell you what we think it is:\n\nit is a star whose gravity is too great for the nuclear fusion in its core to negate.  it collapses in on itself and goes supernova.  then it is a neutron star.  if the gravity is still too great, it collapses some more and becomes a black hole.  its gravity is so strong that light itself cannot escape it (thus it is 'black').  they are suspected to be at the center of many galaxies, especially quasars and other active galaxies.  one is believed to be at the center of our own galaxy, the milky way.\n\nonce again, no one has really seen one, just the indirect evidence that one exists (strange star orbits, gas being sucked into nothing, strange bursts of some kind of rays (can't remember what kind) coming out of the poles, etc.\n\neverybody is pretty convinced that they exist.  its just kinda hard to prove.\n\nps the idiot down there who said black holes are dead galaxies has no clue what he is talking about. please ignore him.  and its not the size of an atom, its an infinitely small point, the swartzchild point.
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No.  A black hole is an immensely dense object, like taking all the matter in our solar system plus more, and condensing it to the size of a pea or so.  The moment we could "create" one, the entire earth would be "sucked into" it.
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Black holes appears when a star doesn't shines anymore and turn into a supernova.  The gravity is so strong that even light cannot escape. That is a rumor that the sun will turn into a bigger star ( not sure if it is because the light runs out or what) after millions of years and it will eat up mercury and after millions of year, the light will run out and the sun will explode and turn into a blavk hole and suck up all the planets.
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The spiral arms and the "halo" in the center, which is thought to be massive amounts of stars and light trapped in an extremly large black hole.\n\nAlso, there is evidence in super nova explosions that show the propable formations of large black holes and, eventually, galaxies.
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There are 16 distinctly different weights and black holes.\n   They are called anti-matter weight activation due to the\n   never defined size, so the inconsistency of measurement\n   is a characteristic of parallel science.  The size of a new \n    star, in orbitting magnetized.\n    So the actual sitings are radion stars.  They are poisonous,\n      hot, exploding, and reshaping local asteroid fields.  This\n     interaction is NOT included in a weight, so the question is\n     purely mathematically theoretic.  The two I have read most\n     about are magnesium one, and pyrite 10.  These weigh\n       Thirty trillion pounds lead weighted to uranium neutron7\n     and 40 trillion etc.  The multiplier here at the end is translated\n     as n factor that is times times, so it is 1million times 1\n       thousand times 100 give or take a factor.  This estimate\n      is now megaplex times 100 plus plus, fields interactive,\n     times one million plus plus again to determine size limitation.\n           Simplistic theories say that this gaseous volume is put\n      in a column cooled to average space temperature safe for\n      orbitting, and megaplex being the highest factor now set\n      for material science at 10 billion megaplex  point 4 billion.\n            A volume number that is assigned to new stars.
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For the most part, globular clusters are larger, being maybe 100 to 250 light years in diameter. By comparison, the North America (NGC7000) and Orion (M42) nebulae are each about 30 ly across, and the Rosette (NGC2237) is about 90 ly. Planetary nebulae are quite small, mostly one light year or so in diameter.\n\nBut many emission nebulae are just locally illuminated parts of much larger clouds, so nebulae can potentially be much larger. The Tarantula nebula (NGC2070) in the Large Magellanic Cloud, is around 1000 light years across.