This won the youtube phylm prize (very prestigious).  Most astronomers believe that all elements other than hydrogen and helium come from supernovae.  So, in many senses, we are stardust.

Much of this understanding springs from the work of Subrahmanyan Chandrasekar in the 1930’s and the Chandrasekar limit (wikipedia). From wikipedia:

“A critical situation arises when iron accumulates in the core, since iron nuclei are incapable of generating further energy through fusion…”

“For more massive stars, electron degeneracy pressure will not keep the iron core from collapsing to very great density, leading to formation of a neutron star, black hole, or, speculatively, a quark star.”

Or the star can undergo a supernova explosion.