Space
AGB Stars: The Carbon Factories That Seed the Universe
Most of the carbon in your body was not made in a supernova. It was made in the bloated outer layers of a dying star on the asymptotic giant branch — a phase of stellar evolution so chemically productive that a single AGB star can enrich the surrounding interstellar medium with more carbon than a thousand supernovae. These stars pulse, dredge up nuclear-processed material from their interiors, and blow it into space in slow, dense winds that eventually become planetary nebulae.