Kilonova

[1] More specifically, the kilonova is an isotropically expanding luminous afterglow of electromagnetic radiation associated with the radioactive decay of r-process nuclei ejected from the merger.

The high sphericity of kilonovae through its early epochs was deduced from the blackbody nature of the spectrum observed for the most important recorded BNS merger, GW170817 / AT2017gfo.

[1] The radioactive glow arising from the merger ejecta was originally called mini-supernova, as it is 1⁄10 to 1⁄100 the brightness of a typical supernova, the self-detonation of a massive star.

[8] On October 16, 2017, the LIGO and Virgo collaborations announced the first detection of a gravitational wave (GW170817[9]) which would correspond with electromagnetic observations, and demonstrated that the source was a binary neutron star merger.

[1] In their work, they suggested that the radioactive ejecta from a neutron star merger is a source for powering thermal transient emission, later dubbed kilonova.

[17] A first observational suggestion of a kilonova came in 2008 following the gamma-ray burst GRB 080503,[19] where a faint object appeared in optical light after one day and rapidly faded.

Artist's impression of neutron stars merging, producing gravitational waves and resulting in a kilonova
Kilonova illustration
Animation showing two small, very dense neutron stars merge via gravitational wave radiation and explode as a kilonova
This artist's impression shows a kilonova produced by two colliding neutron stars.
First kilonova observations by the Hubble Space Telescope [ 18 ]
Fading kilonova in GRB160821B seen by the Hubble Space Telescope .