Californium-254 and kilonova light curves

Understand

Neutron star mergers offer unique conditions for the creation of the heavy elements and additionally provide a testbed for our understanding of this synthesis known as the $r$-process.

• We have performed dynamical nucleosynthesis calculations and identified a single isotope, $^{254}$Cf, which has a particularly high impact on the brightness of electromagnetic transients associated with mergers on the order of 15 to 250 days.
• This is due to the anomalously long half-life of this isotope and the efficiency of fission thermalization compared to other nuclear channels.
• We estimate the fission fragment yield of this nucleus and outline the astrophysical conditions under which $^{254}$Cf has the greatest impact to the light curve.