PROFESSOR PATRICK BRADY

On August 17, 2017, the gravitational-wave signal from a pair of merging neutron stars was detected by the LIGO-Virgo network. A gamma-ray burst, ~2 seconds after the merger, was detected by the Fermi satellite. The source of the signal was localized to about 30 square degrees on the sky using the gravitational-wave data. An optical transient was later identified in NGC 4993, just 130 million light years from Earth. Follow-up observations across the electromagnetic spectrum revealed a mildly-relativistic explosion including a component powered by the radioactive decay of r-process nuclei. After a brief review of the LIGO-Virgo detectors and the gravitational waves predicted by general relativity, the speaker will describe the rich scientific payoff from this discovery.