G=EMC^2 Glazier wrote:
The last days of our sun will be when all its fusion fuel is just about
used up and finds the iron nucleus is to tightly held together ,and
fusion can't take place. The star"s core has been transmuted into iron.
Iron atoms in the universe should be very long lasting. How much iron
does the sun have now? Is there more iron in the solar system than iron
in the sun? Bert


I'm going to kick myself for responding, but:

The Sun will NOT have a core that was transmuted to iron. It lacks the mass to
drive to that process. At best, helium fusion will lead to the formation of
carbon and oxygen. But there is insufficient mass in the core to compress and
heat this inert mass to the point where it will fuse. Instead, the outer
atmosphere will be puffed off over time to form a planetary nebula while the
inert carbon/oxygen core cools to become a white dwarf.

The estimated iron content of the Sun is about 0.1 percent of its mass.