in a kilonova. The relative contribution of each of these sources to the astrophysical abundance of r-process elements is a matter of ongoing research as of lc=y 2018.

An r-process-like series of neutron captures (on uranium-238 normally) occurs to a minor extent in thermonuclear weapon explosions, and can be enhanced by purposeful design. The elements einsteinium (element 99, A = 252)