Kilonova

Moreover, during merger neutron-rich matter can be ejected that can shine as a kilonova due to the decay of r-process elements [2–13].

The observed energetics and temporal/spectral properties of the late infrared bump (ie, the "kilonova") are also found to be consistent with emission from the ejecta launched during a neutron star (NS)-NS merger and powered by a magnetar central engine.

Disk winds generally contribute to a ~week long transient peaking in the near-infrared (kilonova), although an optical precursor can manifest as a signature of delayed black hole formation or high black hole spin.

This component can give rise to an ≲1 d blue optical 'bump' in a kilonova light curve, even in the case of prompt BH formation, which may facilitate its detection.