Small stars like the sun live long and become dwarfs: those can explode only if the "stolen" the fuel of the companion star. The kernel of massive stars quickly collapse, an explosion occurs (sometimes with a gamma-ray burst). The result: a neutron star or black hole. Pressure on the nucleus is so large that the fusion reaction does not stop at carbon.
Small stars like the sun live long and become dwarfs: those can explode only if the “stolen” the fuel of the companion star. The kernel of massive stars quickly collapse, an explosion occurs (sometimes with a gamma-ray burst). The result: a neutron star or black hole. Pressure on the nucleus is so large that the fusion reaction does not stop at carbon. Star continues to turn the light nuclei in all the heavier elements, and each subsequent reaction takes place faster.
The conversion of carbon to oxygen is six hundred years, the oxygen in silicon – six months, and silicon is transformed into iron in a single day. When the core of a star is a ball of solid iron no bigger than Earth and weighing around the Sun, the sentence she signed. Less than a second, it explodes. To iron it all ends, as opposed to the lighter elements of its atoms in a fusion reaction energy does not emit, and absorb. The energy that supports the outer layers of the star stops being produced, and the kernel simply “collapses”. As a rule, the result is a neutron star.
This star is so dense slag that a teaspoon of its matter would weigh a billion tons. From the worst of stars is only all-consuming black hole. It was at this moment, I am sure Woosley – that is, before the collapse is somehow transformed into an explosion – in some supernova is a flash of gamma rays. Woosley became interested in these outbreaks decades ago when they seemed so mysterious phenomenon, what about their origin there were some hundreds of hypotheses varying degrees of seriousness – from star quake “to exhaust the alien spaceships. But when at the end of XX century from Space Observatory Compton Gamma Ray “received information that the sources of gamma-ray bursts lie far beyond our galaxy, it warmed up even more interest in Woosley. Therefore, that these outbreaks were presented to us so bright, they must encompass more energy than you can imagine – and to be much brighter than supernovae. And the source of energy they are likely much more powerful than a normal star. Maybe gamma rays somehow caused by a catastrophic tremor of collapsing stars?
Read more in Physics
« Aussie Girl Solves Missing Mass Mystery of UniverseIn a Galaxy Observed Acceleration of The Rotation of Black Holes »
So, Woosley decided to find out exactly how a collapsing supernova core can produce a flash. He and his colleagues, including Andrew Mac Fad yen of New York University, recreate the explosion mechanism of supernovae using computer models. They start with a very massive star (about forty times more massive than the Sun), rotating so fast that it nearly flies apart. Shortly before his death, the star of the kernel, unable to cope with the force of its own gravity, collapses and turns into a black hole. However, due to the highest speed of rotation of the stars often hit a black hole matter resists her attraction. Around a black hole formed by a rotating disk – a whirlpool in the depths of moribund stars. ”It’s all in the rotation,” – says Woosley. If it were not for it, there would be no drive and without – and gamma-rays. Friction heats the disk rotating around a black hole at speeds of several thousand revolutions per second, up to forty billion degrees. Meanwhile, the disc continues to pour in new matter. After a moment, after the formation of a black hole digging out a jet of hot gas.
The energy of each jet can be supplied directly from the friction in the disk or from most of the black hole through magnetic fields that link it with the surrounding matter. Like its star, gave birth to a black hole rotates at a breakneck pace, forcing the magnetic field to stretch, bend and topple like a rubber band, vbrasyvaya to drive massive amounts of energy.
Anyway, the jet of gas bursting out and reach the surface of the star for some ten seconds. If the star originally kept around her thick belt of hydrogen gas, the jet velocity decreases sharply, and gamma-rays can not follow. But if hydrogen is not (it could carry the solar wind), the jet burst into space at speeds less than the percentage of inferior speed of light.
And here it should flash: inside each jet at high speed face clusters of matter, resulting in the formation stages of fast electrons. Electrons rotate around the magnetic fields of the jet, emitting gamma rays. For many days, until the gas stream hits the outer space and mixes with the rarefied interstellar gas, it causes residual radiation in the visible and infrared spectrum, as well as radio waves. The outbreak, which occurred in February 2006, was not as bright as the most recorded earlier – perhaps the fact that the exploded star was massive enough to form a black hole. Woosley suggests that the same sequence of events – the “collapse”, the appearance of a rotating disk and jets of gas – may also occur in the case when the collapse of a star formation is completed is not a black hole, and a rapidly spinning neutron star. Even at a time when they reach the surface of the star for several minutes before the explosion – said Woosley. - Flash – a precursor of a supernova. “
And yet this is not enough for an explosion. ”If you just skip through the star of the gas stream, – explains Woosley – good supernova will not work. Star will lose much, and then his mother, but most still will draw back. “To make a collapsing star to explode, it is necessary, according to Woosley, “something else”. If we talk about the stars that give rise to gamma-rays, rotating black hole, and drive around it can provide enough energy to break the star to smithereens. However, in most cases, the collapse stops when the core size of the earth is compressed into a neutron star the size of an average city, heated to hundreds of billions of degrees. This is the moment of maximum compression. Clenched core decompressed, causing a shock wave that rushes to the surface by ramming matter, continue to fall toward the center of the star of its outer layers.
Simulation of these and other processes occurring in a supernova requires incredible power of computers, and even the biggest supercomputers can not fully reproduce the explosion of a star in three dimensions. They found that there is a thousandth of a second after the onset of shock, both from the center of the star burst flux of neutrinos – tiny, almost deprived the masses of particles. Neutrinos produced in the collapsing core, draining the energy of the shock wave, it loses speed, and no supernova – at least in the computer model – fails.
A team of astronomers from the University of Arizona under the leadership of Adam Burrows is now working with a computer model, powerful enough to recreate the shaking and convulsions of the collapsing core, and they finally managed to figure out what can cause the star to explode.
Small stars like the sun live long and become dwarfs: those can explode only if the "stolen" the fuel of the companion star. The kernel of massive stars quickly collapse, an explosion occurs (sometimes with a gamma-ray burst). The result: a neutron star or black hole. Pressure on the nucleus is so large that the fusion reaction does not stop at carbon.
Read more: http://scienceray.com/physics/life-and-death-of-stars/#ixzz1OHG2ga00
Small stars like the sun live long and become dwarfs: those can explode only if the “stolen” the fuel of the companion star. The kernel of massive stars quickly collapse, an explosion occurs (sometimes with a gamma-ray burst). The result: a neutron star or black hole. Pressure on the nucleus is so large that the fusion reaction does not stop at carbon. Star continues to turn the light nuclei in all the heavier elements, and each subsequent reaction takes place faster.
The conversion of carbon to oxygen is six hundred years, the oxygen in silicon – six months, and silicon is transformed into iron in a single day. When the core of a star is a ball of solid iron no bigger than Earth and weighing around the Sun, the sentence she signed. Less than a second, it explodes. To iron it all ends, as opposed to the lighter elements of its atoms in a fusion reaction energy does not emit, and absorb. The energy that supports the outer layers of the star stops being produced, and the kernel simply “collapses”. As a rule, the result is a neutron star.
This star is so dense slag that a teaspoon of its matter would weigh a billion tons. From the worst of stars is only all-consuming black hole. It was at this moment, I am sure Woosley – that is, before the collapse is somehow transformed into an explosion – in some supernova is a flash of gamma rays. Woosley became interested in these outbreaks decades ago when they seemed so mysterious phenomenon, what about their origin there were some hundreds of hypotheses varying degrees of seriousness – from star quake “to exhaust the alien spaceships. But when at the end of XX century from Space Observatory Compton Gamma Ray “received information that the sources of gamma-ray bursts lie far beyond our galaxy, it warmed up even more interest in Woosley. Therefore, that these outbreaks were presented to us so bright, they must encompass more energy than you can imagine – and to be much brighter than supernovae. And the source of energy they are likely much more powerful than a normal star. Maybe gamma rays somehow caused by a catastrophic tremor of collapsing stars?
Read more in Physics
« Aussie Girl Solves Missing Mass Mystery of UniverseIn a Galaxy Observed Acceleration of The Rotation of Black Holes »
So, Woosley decided to find out exactly how a collapsing supernova core can produce a flash. He and his colleagues, including Andrew Mac Fad yen of New York University, recreate the explosion mechanism of supernovae using computer models. They start with a very massive star (about forty times more massive than the Sun), rotating so fast that it nearly flies apart. Shortly before his death, the star of the kernel, unable to cope with the force of its own gravity, collapses and turns into a black hole. However, due to the highest speed of rotation of the stars often hit a black hole matter resists her attraction. Around a black hole formed by a rotating disk – a whirlpool in the depths of moribund stars. ”It’s all in the rotation,” – says Woosley. If it were not for it, there would be no drive and without – and gamma-rays. Friction heats the disk rotating around a black hole at speeds of several thousand revolutions per second, up to forty billion degrees. Meanwhile, the disc continues to pour in new matter. After a moment, after the formation of a black hole digging out a jet of hot gas.
The energy of each jet can be supplied directly from the friction in the disk or from most of the black hole through magnetic fields that link it with the surrounding matter. Like its star, gave birth to a black hole rotates at a breakneck pace, forcing the magnetic field to stretch, bend and topple like a rubber band, vbrasyvaya to drive massive amounts of energy.
Anyway, the jet of gas bursting out and reach the surface of the star for some ten seconds. If the star originally kept around her thick belt of hydrogen gas, the jet velocity decreases sharply, and gamma-rays can not follow. But if hydrogen is not (it could carry the solar wind), the jet burst into space at speeds less than the percentage of inferior speed of light.
And here it should flash: inside each jet at high speed face clusters of matter, resulting in the formation stages of fast electrons. Electrons rotate around the magnetic fields of the jet, emitting gamma rays. For many days, until the gas stream hits the outer space and mixes with the rarefied interstellar gas, it causes residual radiation in the visible and infrared spectrum, as well as radio waves. The outbreak, which occurred in February 2006, was not as bright as the most recorded earlier – perhaps the fact that the exploded star was massive enough to form a black hole. Woosley suggests that the same sequence of events – the “collapse”, the appearance of a rotating disk and jets of gas – may also occur in the case when the collapse of a star formation is completed is not a black hole, and a rapidly spinning neutron star. Even at a time when they reach the surface of the star for several minutes before the explosion – said Woosley. - Flash – a precursor of a supernova. “
And yet this is not enough for an explosion. ”If you just skip through the star of the gas stream, – explains Woosley – good supernova will not work. Star will lose much, and then his mother, but most still will draw back. “To make a collapsing star to explode, it is necessary, according to Woosley, “something else”. If we talk about the stars that give rise to gamma-rays, rotating black hole, and drive around it can provide enough energy to break the star to smithereens. However, in most cases, the collapse stops when the core size of the earth is compressed into a neutron star the size of an average city, heated to hundreds of billions of degrees. This is the moment of maximum compression. Clenched core decompressed, causing a shock wave that rushes to the surface by ramming matter, continue to fall toward the center of the star of its outer layers.
Simulation of these and other processes occurring in a supernova requires incredible power of computers, and even the biggest supercomputers can not fully reproduce the explosion of a star in three dimensions. They found that there is a thousandth of a second after the onset of shock, both from the center of the star burst flux of neutrinos – tiny, almost deprived the masses of particles. Neutrinos produced in the collapsing core, draining the energy of the shock wave, it loses speed, and no supernova – at least in the computer model – fails.
A team of astronomers from the University of Arizona under the leadership of Adam Burrows is now working with a computer model, powerful enough to recreate the shaking and convulsions of the collapsing core, and they finally managed to figure out what can cause the star to explode.
Small stars like the sun live long and become dwarfs: those can explode only if the "stolen" the fuel of the companion star. The kernel of massive stars quickly collapse, an explosion occurs (sometimes with a gamma-ray burst). The result: a neutron star or black hole. Pressure on the nucleus is so large that the fusion reaction does not stop at carbon.
Read more: http://scienceray.com/physics/life-and-death-of-stars/#ixzz1OHG2ga00
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