0
All stars "burn" by the process of nuclear fusion.
When fusion has been completed, the star dies.
That can occur in several different ways and the interested party could look into the topic of stellar evolution.
Neutron stars, black holes and white dwarfs are examples of end stages of stellar evolution. Some stars never really reach the stage of fusion and such large objects are called brown dwarfs. If Jupiter were not a planet, it might be deemed a brown dwarf.
Wiki User
∙ 11y ago
Wiki User
∙ 14y agoNeutron stars and pulsars (which are rapidly spinning neutron stars) probably no longer have fusion going on in the core (or at least, not much!), but they once did.
Wiki User
∙ 14y agoA brown dwarf - that is a "failed star". One that didn't have enough mass to start nuclear fusion.
Add your answer:
Earn +20 pts
How are low mass star born?
Low mass stars are created in the same way as all other stars, with one exception. They do not accumulate enough mass to create enough pressure in the core for nuclear fusion to occur. They "glow" because of the external pressure on the core but this is not enough to initiate nuclear fusion.
Why a stars collapses when iron is the only element left in the core?
When hydrogen fuses into helium, extra energy is released, causing more fusion. When helium fuses into carbon, extra energy is released, causing the reaction to continue. When each element fuses into heavier ones, energy is released - until you get to iron.When iron fuses into heavier elements, or when anything fuses into elements heavier than iron, it sucks energy OUT of the reaction, slowing it down. This is like poison to a nuclear reaction; sucking the energy OUT of a star rather than releasing it. The star dies instantly, and the collapse causes a titanic explosion in which even MORE energy is sucked out of the core of the star, as heavy elements fuse into heavier ones, until the heavy elements like Uranium and thorium are so massive that they cannot hold together and begin to fall apart._____________________________________________________________________The above answer isn't exactly right. An over simplification.Normal stars, like our sun, live just long enough to begin fusing helium into carbon. At that stage, they generate so much energy that they essentially boil off their outer layers, in a stellar nova. Eventually they boil off everything but their inner carbon core, leaving a white dwarf. But giant stars, like Betelgeuse, have enough mass to hold together. This mass, and the immense force at the stars core, provides enough energy to fuse carbon into heavier elements.Nuclear fusion is not easy. So far we have only achieved it through a two step reaction, beginning with a nuclear fission explosion. You have to put energy in to get energy out. The reason is the electromagnetic charge of the atomic nucleus. The nucleus is made of positively charged protons and neutrally charged neutrons. It takes a lot of force to overcome these charges. The bigger the nucleus, the more force required to fuse it.So, after fusing all of its available helium into carbon, the star is on borrowed time. Each stage in the star's fusion cycle is shorter than the last, simply due to the availability of the fuel. After billions of years of fusing hydrogen, millions of fusing helium, time quickly runs short. Carbon fusion last about 600-1000 years. Carbon fusion produces neon, neon fusion lasts roughly 1 year. Next is oxygen fusion, lasting maybe 6 months, producing silicon. But then, something strange happens. In every previous step of the fusion cycle, fusion produces more energy than it consumes, but iron is the other way around. Silicon fusion produces iron, but iron fusion requires too much energy, effective ending all nuclear fusion at the core. Silicon fusion lasts 3-5 days, and at that time there is not enough energy left in the core to fuse anything, and the core collapses under the weight of the stars mass. This collapse goes until protons an neutrons are crushed together so tight the the entire mass becomes pure neutrons. This stops the collapse momentarily, sending enormous shock waves through the stars outer layers, causing massive runaway nuclear reactions, blasting the star apart in a type II super nova. The runaway nuclear reactions produce elements heavier than iron through neutron accumulation. At the core, one of two things happens: Either the nuclear forces stop the collapse, forming a neutron star, or the force of the collapse overpowers the nuclear forces, and the core collapses into a black hole.On a related note, the star Betelgeuse, mentioned earlier, is a red super giant, and is believed to be rapidly supernova. In fact, given its distance of over 800 light years away, it is likely that it already has gone supernova. When it does, or rather when the supernova's light reaches earth, it will outshine even the full moon in the night sky, and be easily visible in broad daylight. The supernova will last about 6 mouths, before fading away for good. It should produce a neutron star.______________________________________The above statement "Nuclear fusion is not easy. So far we have only achieved it through a two step reaction, beginning with a nuclear fission explosion." is not completely true, referring to the "so fare we have only" part. We have achieved cold fusion by using super conducting magnets to drive hydrogen particles into each other. They reach speeds near light speed, then clash into each other. If the collision is direct enough they will fuse into helium. This produces far more energy than the energy used to crash them into each other. Once we find a way to harvest that energy we can create cold fusion reactors.________________________________________Well, just a small addition. Fusion has been accomplished with lasers also. Work at the National Ignition Facility Lawrence Livermore Laboratories, has produced small fusion reactions and they hope to create a sustained reaction at some point.
What is the difference between a sun and the protosun?
The protosun has not fully "ignited" meaning nuclear fusion is not stably providing the energy output of the star. Once ignition takes place, the central core of the sun will produce energy almost exclusively through fusion, creating enough energy and radiation to slowly wash away the nebulous gas surrounding the protosun revealing the sun itself.
What is the evolution sequence of a red dwarf star?
Your red dwarfs are stars (fusion in core). Objects of .4-8 solar masses will all become stars and then go through the red giant, planetary nebula and white dwarf stages (just like the Sun), but so will red dwarfs which have .08 - .4 solar masses (it just takes them "forever").
What do blue super-giant and red or yellow dwarf stars evolve into?
The endgame for any star depends upon its mass. Blue stars, typically class O, are very massive, and will eventually nova (supermassive stars that nova with exceptional violence are termed supernovas, again, a function of the star's mass) after all or most of the hydrogen has been fused into helium. A large chunk of mass is blown off during the nova stage, and the star collapses. The collapse heats the core and triggers the fusion of helium. This can continue a considerable number of times, until the star is actually forming iron. All elements above iron on the periodic table can be be fused with themselves to form the next element in an exothermic reaction, meaning it generates energy in addition to the new element. Iron fused to iron is endothermic, it takes more energy to make it fuse than the fusion produces. The final nova will then see the core collapse yet again, but without a new fusion reaction to stop the collapse, the core will collapse to for "degenerate matter", a neutron star, or potentially a quasar. Extremely massive stars may, theoretically, form black holes instead, as the core collapse is so violent even neutron star matter cannot withstand the pressure, and the entire mass of the star is collapsed down to a single point. Dwarf stars are, of course, far less massive. When they use up their hydrogen, they swell into a red giant, then collapse back down. Low mass stars may retain too little mass to start the next fusion cycle, and will become a white dwarf. Larger stars may be able to stand a few cycles of new fusion, but soon will not retain enough mass to start another, and also shrink to white dwarf stars. Over time, the white dwarf stars will cool and become brown dwarf stars. A sun the size of Sol would expand enough as a red giant to very near Earth's orbit, which will be very bad news for anyone here in a few billion more years.
What is the light source of stars?
Nuclear Fusion at the Stars' Core.
What is the atomic process that occurs in the core of stars?
Nuclear Fusion occurs in the core of stars.
What is the site of nuclear fusion on the sun?
If you are asking where does solar nuclear fusion take place, then that would be at the core of stars.
How does Betelgeuse emit light?
Like all stars, Betelgeuse emits light because it is very hot. The heat for that light comes from nuclear fusion reactions occurring in the star. Unlike in most other stars, the fusion is occurring in a shell around the core rather than in the core itself.
What is the reaction that happens in a stars core is?
nuclear fusion
What is the source of a star's light?
Nuclear Fusion at the Stars' Core.
How is energy created in a stars core?
As with our Sun (a star) by nuclear fusion.
The hottest part of the sun?
The very center of the core, where nuclear fusion is occurring; millions of degrees.
What is the mechanism which all the stars produce electromagnetic radiation?
Nuclear fusion in the core.
How do stars create all elements up to iron in their core. What if your answer?
The process is called stellar nucleosynthesis and is based on nuclear fusion reactions.
What fusion in stars occurs to create the element helium?
Hydrogen undergoes nuclear fusion in the core of the sun to form helium.
What part of the sun is the hottest?
The very center of the core, where nuclear fusion is occurring is the hottest part of the sun. It's millions of degrees!
