I think the heavier elements exponentially speed up stellar death. In part, the fusion of elements makes the core denser and denser each step of the way. Going from hydrogen to helium is twice as dense, but helium is still a good fuel so it isn’t an issue. As fusion continues through carbon and oxygen, it shrinks but still burns. Iron is the tipping point though because it doesn’t work as a fuel at all - it triggers a core collapse, the surface falls into the void, and everything heavier than iron is instantaneously fused and thrown into the universe.
So I would guess the lesser abundance of heavier elements early on delayed that process compared to today’s standards. Sort of like making a snowman in fresh powder and having to melt/wet the snow to make it pack vs having a little rain and higher temps after the powder to wet it
The amount of heavy elements present in a star when it formed will be neglible to the amount that will be created over time through fusion.
You can actually detect this through spectroscopy because the initial amount of metals will be present in the outer layer of the star. Heavy elements made through fusion will be mostly in the core.
The reason stars formed from primordial gas, i.e. only consisting of hydrogen and helium, is that such a gas will fragment less as it cools and collapses. Less fragmentation means heavier stars.
I only have a high level knowledge of the process though.
I think the heavier elements exponentially speed up stellar death. In part, the fusion of elements makes the core denser and denser each step of the way. Going from hydrogen to helium is twice as dense, but helium is still a good fuel so it isn’t an issue. As fusion continues through carbon and oxygen, it shrinks but still burns. Iron is the tipping point though because it doesn’t work as a fuel at all - it triggers a core collapse, the surface falls into the void, and everything heavier than iron is instantaneously fused and thrown into the universe.
So I would guess the lesser abundance of heavier elements early on delayed that process compared to today’s standards. Sort of like making a snowman in fresh powder and having to melt/wet the snow to make it pack vs having a little rain and higher temps after the powder to wet it
The amount of heavy elements present in a star when it formed will be neglible to the amount that will be created over time through fusion.
You can actually detect this through spectroscopy because the initial amount of metals will be present in the outer layer of the star. Heavy elements made through fusion will be mostly in the core.
The reason stars formed from primordial gas, i.e. only consisting of hydrogen and helium, is that such a gas will fragment less as it cools and collapses. Less fragmentation means heavier stars.
I only have a high level knowledge of the process though.
Thanks for the explanation! :)