Do all stars produce iron, including the sun?

No, not all stars have iron in them.

Iron can only be produced in massive stars (more than 8 times the mass of the Sun), which does not include the Sun. The Sun is a low-mass star.

In low-mass stars, nuclear fusion reactions can only produce carbon and small amounts of nitrogen, oxygen, neon and trace amounts of light metals, and eventually slowly lose their gas outer layer in the form of a star wind and become a white dwarf. In the later stages of evolution, massive stars will continue their fusion reactions until iron is formed inside due to their large mass, strong gravitational pull, and high internal temperature and density. Therefore, iron can only be produced in massive stars.

The sun contains iron. But the iron in the sun is not generated in the sun, but brought in when the sun is formed. Because the Sun is at least a second-generation star.

When the first generation of stars reached the end of their evolution, and the massive stars in them died out in the form of supernova explosions, a large number of heavy elements were scattered in the universe, mixed with the original interstellar gas clouds, and new stars were born from them, which is the second generation of stars. That is, when the second generation of stars is born from the interstellar gas cloud, the interstellar gas cloud has been "polluted" by heavy elements such as iron produced in the previous generation of stars, so there will be heavy elements such as iron on the sun.

*Not all stars produce iron, including the Sun, and they can't produce iron**. Only in stars with masses more than 8 times greater than the Sun can nuclear fusion continue until iron is formed. The mass (gravity) of a star like the Sun is too weak to cause the carbon inside the star to continue to coalesce into oxygen, so when the Sun fuses all the helium into carbon, it will be completely extinguished.

No, our sun has a lifetime of 10 billion years, and it is a medium-mass star, which can only fuse to carbon, and only 8 or more solar masses can fuse to iron.

Because the energy of a single nucleon (proton, neutron) in the iron atom is the least compared to other elements, the energy provided in the fusion reaction is very limited, but the external conditions for the fusion reaction are very harsh and require extremely high temperatures.

When an iron core is formed inside the star, due to the above reasons, the iron element does not undergo a fusion reaction, the star has no outward expansion force, the expansion force of nuclear fusion gradually weakens, gravity dominates, and the balance that supports the existence of the star is lost.

When stars of different masses collapse, they form novae, supernovae, extreme supernovae, and gamma bursts.

Iron is the element that needs the most binding energy, and in the end, there is not enough energy to fuse iron. Heavier than ferrite comes from slow neutron capture, and after decay it becomes an element heavier than iron.

The universe is very vast, and the mystery of the mountain nucleus in the universe is still unknown to us. Perseverance in decomposing why high-speed rail is suspended is still a question that plagues science now.

The elements of iron in the universe are mainly formed through the process of neutron capture, and it is also possible that they were formed during the merger of binary neutron stars.

It is not the stellar upheaval that produces iron, but the generation of iron that destroys the star.

Stars are stabilized by the outward and inward gravitational forces produced by internal nuclear fusion reactions. In massive stars, the first thing that happens is the reaction of hydrogen fusion to helium, and the resulting helium is deposited in the inner core. The nuclear fusion reaction of hydrogen is transferred to the surface of the central helium sphere.

When the hydrogen is almost consumed, the helium inside the star accumulates to a certain extent, and because there is no outward radiation pressure, it can only shrink inward. The contraction increases the pressure and temperature inside, and the density also increases, to a certain extent, which can trigger a nuclear fusion reaction in which helium fuses to carbon, and the center changes from helium to carbon. In this way, the elements produced and deposited in the center became heavier and heavier, and the atomic weight increased.

From the center outward, the various elements are layered around the perimeter, and the outward it is, the lighter the element. Various nuclear fusion reactions take place at the interface of the layers.

The various nuclear fusion reactions are carried out sequentially until the element iron appears in the center of the star. At this point, the internal structure of the star looks like this (this image is not drawn to true scale).

The energy produced during the fusion of elements is related to the internal energy of the nucleus. The lighter the element, the more energy is produced when it is fused, and the heavier the element, the less energy is produced when it is fused. Whereas, the elements heavier than iron are all produced by the fission of atomic nuclei.

The heavier the nucleus of a fissile element, the more energy it produces, and the lighter the nucleus, the less energy it produces. Only iron cannot release energy through fusion or fission. In order for iron to continue fusion, not only can it not extract energy from it, but it must also provide energy to the nucleus.

The internal energy of the nucleus of each element is roughly shown in the figure below.

It is precisely because of this property of the element iron that once iron is produced in stars, the nuclear reaction can no longer continue. At this point, iron accumulates in the center of the star, more and more, forming a core composed of iron.

When the nuclear fusion reaction inside the star is terminated by iron, and no new nuclear fusion reaction occurs, there is no release of energy, no outward radiation pressure, gravity will prevail, and the star will shrink sharply inward. According to calculations, the outer layer of matter can even approach the speed of light as it shrinks inward and approaches the iron core in the center. But the iron in the iron core exists in an electron degenerate state and cannot be compressed.

When the outer layer of material hits the iron core, it is like hitting an incredibly hard wall. Once the matter hits this wall, it will go out at almost the same speed**, and at the same time bring strong kinetic energy to the iron core, it will rush out of the star in the form of an implosion, forming a supernova explosion. This process is called the "Iron Heart Cataclysm".

This is the end of a star's life.

At the same time that the star throws matter and energy outward in the form of a supernova explosion, and with the kinetic energy input brought by the inward collision of the outer material, the iron core finally meets the energy requirement to continue to synthesize the nuclei of heavier elements, and larger and heavier elements such as cobalt, nickel, copper, lead, gold, silver, and uranium are formed. Some of them will be thrown out of the stars along with the material thrown outwards and scattered in space, eventually becoming the raw materials for the formation of other planets. This is how the iron on our earth, and the elements heavier than iron, come from.

Stars will not turn into large iron balls in the end, and after nuclear fusion is extinguished, stars will become dark matter planets, that is, black holes. Well.

Stars don't eventually form a large iron ball, because the iron produced by nuclear fusion is still reused after tens of thousands of years.

Stellar nuclear fusion, after a series of chemical reactions, will turn into iron, but the star does not form a large iron ball, because after becoming iron, the star will continue to evolve into other elements.

Stars are fine.

Stars are fusion-induced high-temperature plasma, the least massive stars, currently presumed to be times the mass of the Sun. Before fusion to iron, it is a process of releasing energy, so hydrogen-helium-lithium ......You can fuse all the way down to iron. Iron refusion is an energy-absorbing process, and stars with too little mass cannot continue.

Stars that are more than 8 times the mass of the Sun, because they are too massive, can continue to fuse as they collapse.

Celestial bodies with less than a double solar mass are not called stars, they are called brown dwarfs. Stars larger than 120 times the mass of the Sun are too violent, extremely unstable, and prone to disintegration.

First of all, it is necessary to understand the properties of the iron atom, the energy of a single nucleon (proton, neutron) in the iron atom is the least compared to other elements, and the energy provided in the fusion antispring block is very limited, so the external conditions for the fusion reaction are very harsh, even for massive stars.

After the formation of iron cores inside the star, the iron element does not undergo fusion reaction to provide the star with outward expansion force, and the expansion force of the nuclear fusion in the state of stupidity gradually weakens, so the gravitational force prevails, the force supporting the star is out of balance, the star will collapse inward under the strong gravitational force, and the star will inevitably escape the fate of destruction.

Stars are first produced by hydrogen fusion to form helium, and the inner layer is made from helium to lithium, and then beryllium in turn. Boron. The larger the star, the greater the internal pressure, the more it can continue to fuse, but when the fusion reaches iron, because the iron is very stable, the energy of the star decreases because the iron is very stable, and the external material begins to collapse inward, collapsing to a certain extent, and when the internal pressure is extremely large, it will continue to fuse by the huge pressure generated by **, and the star is called "supernova" after being observed by people to this rubber chop