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High mass main sequence stars do in fact become red giants. These massive red giants are called red supergiants. They are usually between 10 and 40 solar masses and are 50,000 to 400,000 times as luminous. The best known example is Betelgeuse in the famous Orion constellation. These stars only live for about 5 to 15 million years so they are usually rare.
First you have to understand that all stars go through the main sequence stage. Main sequence means converting Hydrogen to Helium via Fusion. After that the mass and density of a star denotes what it becomes. Our sun will become a Red Giant, but will not go Nova. Stars like VY Canis Majoris will go Nova, and probably be either a Neutron Star or a Black-hole. High mass Stars are already beyond the Red Giant stage.
What else can I help you with?
Does It takes less and less time to fuse heavier and heavier elements inside a high-mass star?
Yes, it takes less time to fuse heavier elements inside a high-mass star because the higher the mass of the star, the higher the core temperature and pressure, which accelerates nuclear fusion reactions. As the star runs out of lighter elements to fuse, it progresses to fusing heavier elements at a faster rate until it reaches iron, at which point fusion stops and the star undergoes a supernova explosion.
Why can't a star fuse chemical elements beyond iron?
It sure can - and some stars do, to a minor degree. However, it can no longer gain energy from this fusion - it costs energy to create heavier elements. --- To fuse Iron, you would need a huge amount of heat and pressure, higher than what can be provided by even the massive stars is existence. The upper limit of a stars mass puts this limit on what materials it can fuse. Elements heavier than Iron are created during a supernova explosion, the death of a massive star.
What conditions of a supernova cause elements that are heavier than iron to form?
Because for a star to fuse elements heavy elements (iron and heavier) it would actually consume energy rather than liberate it. That doesn't work well to keep the star "alive." The explosion of the supernova itself can create these heavier elements because of the heat of the blast.
How does nuclear fusion create elements inside stars?
Nuclear fusion in stars involves the process of combining lighter elements, such as hydrogen, to form heavier elements, such as helium. As these elements fuse together, they release energy in the form of heat and light. Over time, through a series of fusion reactions, heavier elements are synthesized, up to iron, in the core of stars.
Can the sun produce elements heavier than oxygen?
The heaviest element that our Sun produces is probably silicon; the core temperature and pressure would need to be MUCH higher to produce heavier elements. The heaviest element that can be produced in ANY star is iron.The reason for this is something called the "packing fraction curve". As light elements are fused into heavier elements, they release energy; this is how the Sun and other stars work, by fusing hydrogen into helium. Toward the end of a star's life, the temperature and pressure increase enough to fuse helium into carbon, and then carbon into heavier elements, but each stage releases less and less energy. Finally, when elements fuse into iron, you can get no more energy out. To fuse iron into heavier things, or anything into elements heavier than iron, you must put energy IN. When a star begins fusing iron into heavy elements, it suddenly stops producing energy to support the star against the tremendous gravity, but instead starts sucking energy OUT of the core of the star to power fusion!This loss of energy from the core of the star causes a sudden and catastrophic implosion as the core of the star collapses the core into a black hole or neutron star, and the outer layers of the star are compressed and expelled in a shock wave that creates gigatons of heavy elements and throws the remainder of the star's mass into space; a supernova explosion.So, nothing heavier than iron can be produced in a normal star; heavier elements are only created in supernovas.
What fuel is used by red giant stars?
After using up its hydrogen-1, the star becomes a red giant. It will start fusing helium-4 into heavier elements. It may also fuse heavier elements, to get other elements that are yet heavier.
Does It takes less and less time to fuse heavier and heavier elements inside a high-mass star?
Yes, it takes less time to fuse heavier elements inside a high-mass star because the higher the mass of the star, the higher the core temperature and pressure, which accelerates nuclear fusion reactions. As the star runs out of lighter elements to fuse, it progresses to fusing heavier elements at a faster rate until it reaches iron, at which point fusion stops and the star undergoes a supernova explosion.
What does nucleur fusion create inside stars?
First hydrogen nuclei fuse to form helium, and then as the star ages heavier and heavier elements are formed.
What happens with fusion of heavier element?
When heavier elements undergo fusion, they release energy in the form of light and heat. This process can only occur in extreme conditions, such as the high temperatures and pressures found in stars or during a thermonuclear reaction. Fusion of heavier elements can lead to the formation of even heavier elements and can release a tremendous amount of energy.
Did gravity pulled the atoms together to form heavier elements?
Yes, gravity plays a role in pulling atoms together in stars to form heavier elements through nuclear fusion. In the intense pressure and temperature conditions of a star's core, lighter elements like hydrogen fuse together to form heavier elements like helium, carbon, and oxygen.
How are elements heavier than hydrogen formed?
Elements heavier than hydrogen are formed through nuclear fusion processes in stars. When lighter elements fuse together in the intense heat and pressure within a star's core, they can form heavier elements. This process continues throughout a star's life until elements up to iron are created. Elements heavier than iron are formed through supernova explosions or in the collisions of neutron stars.
Define the stellar theory?
If your referring to Stellar Nucleosynthesis, then its when stars fuse the smaller elements (Hydrogen,Helium) to make the heavier elements (iron, gold, silver,zinc, etc).
Why do fuel is required for fusion?
Technically, any elements less massive than iron can fuse together; however, practically it is easier to fuse the lightest elements (Hydrogen, Helium...), which also give higher energy yields. Any elements which are heavier than iron (or are iron) will not fuse, and instead decay via nuclear fission.
Why can the Sun not produce heavier elements beyond carbon and oxygen?
The Sun can only produce elements up to carbon and oxygen through nuclear fusion in its core. For elements heavier than carbon and oxygen, higher temperatures and pressures are required, which can only be achieved in more massive stars or during supernova explosions.
What is the source of all the elements in the universe that are more massive that iron?
The only thing that can fuse lighter elements into something heavier than iron is the explosion of a super-nova star. The problem is something called the "packing fraction". If you fuse light elements like hydrogen into heavier elements like helium, it generates energy; this is how a star works. When the star gets old, it collapses a little, heats up a LOT, and begins to fuse helium into carbon. This releases energy too, but not as much. As you fuse heavier and heavier elements, you get less and less energy out - until you get to iron. From the standpoint of nuclear reactions, iron is as "dense" as things get. Fuse elements together into something heavier than iron, and you must put energy IN to drive the reaction. So in a dying star, getting hotter and hotter and fusing heavier and heavier stuff, at some point it starts fusing iron - and this sucks energy OUT OF the star. Instead of the core of the star feeding energy out to the rest of the star, the core starts sucking energy from the rest of the star into the core, as iron becomes heavier elements like gold, lead, uranium, and even heavier exotic elements. So the middle levels of the star explode in two directions in the supernova - IN, to feed energy to the core to continue the generation of heavy elements, and OUT, to blow the remainder of the star into space. Some of the core elements collapse into a neutron star or a black hole, while the remainder of the core material is blown out into space. Millions or billions of years later, that gold dust or lead dust or uranium dust will fall into another planetary nebula, and form planets - planets like Earth. Every atom of ANYTHING heavier than helium has been through a star - and every atom heavier than iron has escaped from the core of a supernova explosion!
The death of a star occurs when?
When the star runs out of fuel. Most stars burn (fuse, actually) hydrogen. When this runs out, what happens next depends on the mass of the star... heavier stars can fuse heavier elements for a short time, but lower mass stars simply collapse into white dwarfs.
What are some characteristics of stars that might account for the fact that some have more complex elements in their spectra?
Older age might account for it. As a star ages, it uses up the simplest elements (hydrogen . . . helium . . .) then starts fusing heavier and heavier elements. Our Sun will get to the point of fusing iron, which is pretty heavy, but the truly large stars out there will fuse elements much heavier than Iron. These heavier and heavier elements may account for some stars having more complex elements in their spectra.
