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Earth and Space Sciences · Glossary

What is Neutron-star merger; kilonova?

Also known as: neutron-star merger · kilonova

Definition 30.8 University Earth and Space Sciences — Year 3 · Chapter 30 — Where the Elements Come From

A neutron-star merger is the coalescence of two neutron stars in a close binary, whose orbit has shrunk by the emission of gravitational waves. Part of the neutron-rich matter is flung out. A kilonova is the transient glow of that ejecta, heated by the radioactive decay of the freshly made r-process nuclei, which lasts for days.

The galaxy NGC 4993 photographed by the Hubble Space Telescope after the merger of two neutron stars detected in gravitational waves on 17 August 2017. The box marks the kilonova; the insets, taken on 22, 26 and 28 August, show it fading over six days. NASA and ESA (A. J. Levan, N. R. Tanvir, A. Fruchter and O. Fox), CC BY 4.0.
The galaxy NGC 4993 photographed by the Hubble Space Telescope after the merger of two neutron stars detected in gravitational waves on 17 August 2017. The box marks the kilonova; the insets, taken on 22, 26 and 28 August, show it fading over six days. NASA and ESA (A. J. Levan, N. R. Tanvir, A. Fruchter and O. Fox), CC BY 4.0.
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