Plutonium

Plutonium is a synthetic, highly radioactive metal primarily produced through human-made nuclear reactions. It is not naturally occurring in significant quantities in the universe and holds minimal astronomical relevance. As part of the actinide series, plutonium's synthetic nature and limited presence beyond Earth render its role inconsequential in astronomical observations, stars, or cosmic bodies. Its various isotopes have relatively short half-lives, ranging from minutes to thousands of years, contributing to its scarcity and fleeting existence in celestial environments.