[SymeAaro (OP)]

Hello, just doing some research and found that the Sun is around 1% metal. 0.1% of which is iron. Now I've studied nuclear fusion at an in depth level, and I'm pretty damn sur en that the Sun is still in its hydrogen core fusion stage. The only elements it should be synthesising, I though, was helium, from all the hydrogen it has. It only starts fusion of helium into carbon after becoming a red giant, and a thought, being a low mass star, that at no point in its life would it manufacture oxygen, silicon, neon magnesium or iron. Why is there metals in it? Is it residue from when the Solar system formed - i.e debris that accumulated, and that it did not form itself; OR have I missed something important, and the Sun is in fact manufactring heavy elements at this point?
Any help would be greatly appreciated!
Thanks.

[Kryptid]

The Sun is currently believed not to be a first generation star. There would indeed have been heavier elements present in the molecular cloud from which the Sun formed, having been put there by stars that have since come and gone.

[evan_au]

1% metal...at no point in its life would it manufacture oxygen, silicon, neon...

As you observe, astronomers have a unique definition of "metal": They include anything other than Hydrogen & Helium.
And the Sun is too small to achieve the temperatures & pressures to generate these elements.

The Sun is currently believed not to be a first generation star.

Astronomers categorise stars by their metallicity into "Populations" of stars.
They called the most common stars around us (including the Sun) as "Population I" stars.They have high metallicity.

We now believe that the Sun is about a 3rd-generation star, built from the remnants of exploded "Population II" stars (where "II" = 2, in Roman Numerals).

It is thought that the first very stars ("Population III") had almost no metals; they are thought to have exploded long ago, and cannot be seen in our galaxy today.

See: https://en.wikipedia.org/wiki/Stellar_population#Population_I_stars

[puppypower]

How is it possible humans can generate higher atoms  but the sun cannot? Humans have made 26 artificial elements, yet the sun is powerless to make larger atoms than the smallest?  There appears to be a psycho-socio-political element to this theory. 

Here is a better theory that puts the sun in the proper place. If you took a piece iron and placed it in water, it would sink. This is due to the iron having a higher density than water. If we now fabricated the iron into the hull of a toy boat, now the same weight of iron can float on the water. The reason is, density is mass/volume. In the case of the iron boat, we used the same mass of iron but we increased its effective volume, by fabricating the iron into the hull of the boat. The effective density of the iron was thereby lowered below that of water.

In the core of the sun, heavy atoms like iron will not be fully ionized, but will contain some inner electrons. This increases the effective volume, like the hull of an iron ship, allowing iron to float on lighter atoms that are fully ionized; like hydrogen and helium. The ratio of atomic to nuclear volume is 10¹⁵. If iron has even one election, its volume is huge compare to a proton. The iron ship, with one election, can float on compressed hydrogen protons.

In the earth, iron will sink to the core, because all the atoms in the mantle have inner and outer electrons and therefore iron has higher density. One is comparing apples to apples. But the sun is different, since its heat from fusion will ionize smaller atoms completely but not for all atoms, essentially creating a density inversion where the smaller atoms with no elections are the densest, and larger atoms with even one electron are less dense.

The result is the fusion core is surrounded by a shell of larger atoms that float above a small atom fusion core. This shell helps to control runaway fusion. If the core is burning too hot, the higher heat will ionize an electron or two from the shell atoms, making the shell denser. The shell contracts and seals the core, restricting fuel diffusion. This allows the core to cool; sun spot. Once it cools, electrons are added to the shell, and shells fluffs out, allowing more fuel to enter. A sudden fusion surge can create a solar flare. 

These local fusion surges in the core, will hit the shell with tremendous force, like hammer hitting a bell, to create what I call, fusion hammer. Fusion hammer allows larger atoms to be created in the shell, which become part of the shell. Up to the formation of iron, fusion hammer is exothermic. This means internal heat is added to the shell, that comes from the shell, so it contracts when hit, which limits diffusion of formed atoms away from the shell.

Eventually the shell gets too thick and begins to impact the diffusion needed for core fusion, to where the core cools more and more, so the shell can expand more and more, for needed fuel diffusion. The result is a sudden large scale fusion hammer surge, that can clean the pipes, providing materials for planet and asteroid formation.

[Bored chemist]

There appears to be a psycho-socio-political element to this theory. 

It may appear that way to you but I doubt it does to anyone else..

It's perfectly possible that the sun does make heavier elements than uranium- but not much.
We wouldn't be able to detect them from here.

[Janus]

How is it possible humans can generate higher atoms  but the sun cannot? Humans have made 26 artificial elements, yet the sun is powerless to make larger atoms than the smallest?  There appears to be a psycho-socio-political element to this theory. 

Man creates higher elements via the following process.  You bombard a particular isotope of an existing element with neutrons, which creates an isotope of this element with a larger number of neutrons.  This unstable isotope then undergoes a natural beta decay where it emits an electron  through the conversion of a neutron to a proton, which results in an element with a higher atomic number then you started out with.
This requires a number of things:  You need a sample of the initial isotope.  This can often be non-common isotope in naturally occurring samples of this element, so you are going to first separate it out from the naturally occurring source.
You are going to also need a neutron source, which generally an isotope of some element that undergoes alpha particle decay.  The alpha particles produced then have to passed through a medium that strips away the protons and just leaves the neutrons. This is important because the protons, being positively charged, would be repelled by the protons of the neutrons in the target nucleus, preventing their insertion in to the nucleus.  Isotopes that undergo alpha decay are already high up on the periodic table.
The Sun, being composed of, for the most part, Hydrogen and Helium, has no significant concentrations of higher elements that have isotopes that can act as the target for neutrons, nor ones to provide the neutron source, nor are they likely to be concentrated together in just the right way for element synthesis.
The only way the Sun has to create higher elements is by direct fusion; forcing separate nuclei together to form a single nucleus.  This however requires overcoming the natural Coulomb force that pushes them apart.  This in turn, take extremely high pressures and temps.    And while you do get a net energy release from this fusion, the amount of work it takes to force the nuclei together increases as you go up the periodic table and the energy released per fusion decreases.  Our Sun simply doesn't have the mass to cause the internal conditions needed to cause any fusion beyond Helium fusing to Carbon.

The heaviest element that man has been able to synthesize through fusion is Helium from Hydrogen, and even then, the Hydrogen we used was in the form of a rare isotope.

[evan_au]

How is it possible humans can generate higher atoms but the sun cannot?

Stars cannot generate elements higher than Iron-56 by nuclear fusion - and it takes a very large star (much larger than the Sun) to achieve the necessary temperatures and pressures to produce Iron-56.

Some elements slightly heavier than Iron-56 can be produced in the fury of a supernova - but it is thought that this can't produce elements much beyond gold. Certainly not the amount of Uranium that we find in Earth's crust.

A current theory is that elements well beyond Uranium are sprayed into space during the collision and merger of neutron stars. The short-lived isotopes would decay to more stable ones (like Uranium-235) by the time we search for them today.

See: https://en.wikipedia.org/wiki/Nucleosynthesis

[chiralSPO]

How is it possible humans can generate higher atoms  but the sun cannot?

How is that humans can make hot chocolate and the sun cannot?

[chris]

A current theory is that elements well beyond Uranium are sprayed into space during the collision and merger of neutron stars. The short-lived isotopes would decay to more stable ones (like Uranium-235) by the time we search for them today.

I didn't know that; I thought that those beyond-iron massive elements were all products of supernova explosions. Maybe I was wrong to begin with, or have astrophysicists more recently revised their thinking on this?