Kilonova:
Even before such evidence emerged, back in 1974, David Schramm and James Lattimer at the University of Texas at Austin proposed that a different cosmic smash-up might be the source of gold instead. If what we need to make heavy elements is a lot of neutrons, then perhaps their origins involve neutron stars? These are incredibly dense balls of matter – mostly neutrons, as the name suggests – left behind after certain kinds of supernovae. Neutron stars often form in pairs, then spin around each other until eventually smashing together in a cataclysmic explosion called a kilonova. The tide of neutrons that results, reckoned Schramm and Lattimer, could be enough to kick-start the r-process. [“How is gold made? The mysterious cosmic origins of heavy elements,” Sapphire Lally, NewScientist (24 July 2021, paywall)]
