Question

Our sun will first become a red giant star when it leaves the Main Sequence, as it goes from core Hydrogen burning to shell Hydrogen burning. After it has exhausted all of the fusion reactions possible, perhaps some Helium fusion in there as well, it will leave a corpse called a White Dwarf, where there is a crystalline core of carbon and mixed ash products, surrounded by

Answer 1

Individual burning char particles have been described as a shrinking carbon core, as the carbon surrounding....... the mineral matter volatalizes, the size of the individual char particles is reduced significantly.

Typically the coarsest particles in a fly ash are unburned coal char or coke.

Being similar to coal, although essentially devolatized, these char particles contain smaller inclusions of inorganic mineral matter. It would be desirable to have a method which can be operated in such a way as to combust the residual carbon char in the fly ash.

When the star first runs out of hydrogen to fuse in its core it will behave similarly to lower mass red giants. It will first begin fusion of hydrogen in a shell around the core and the core will heat and fuse helium into carbon. There will also be carbon and helium fusion into oxygen. The star's envelope also bloats out to very large sizes.

Super giants core will fuse very heavy elements from carbon and oxygen all the way up to Iron.