Superheavy elements forged in giant stellar collisions

Neutron star merger

Source: © Los Alamos National Laboratory/Matthew Mumpower

Nuclei with mass numbers above 260 are produced in r -process events

Clear evidence of nuclei produced by fission has been discovered in the emission spectra of stars in the Milky Way. These fission fragments, which have been predicted by theoretical models but never previously observed, suggest that events like neutron star mergers and possibly some supernovae produce elements that are heavier than any of those previously seen in nature.