Thanks to the Integral satellite, astrophysicists from the Irfu demonstrated that the wave of August 17 was associated with a gamma ray burst, a brief surge of gamma rays emitted just two seconds after the fusion of the stars. Aiming one of the giant telescopes of the Very Large Telescope (Chile), the scientists also participated in studying the emission of visible light that followed this event, establishing in particular that this light was not polarized.

Unlike the four gravitational waves previously detected, this space vibration, named GW170817, did not result from the fusion of two black holes but from the fusion of two neutron stars, which are the densest known stars.

The particle physicists at Irfu also analyzed the data collected by the Antares and Hess experiments. This shows that wave GW170817 did not give off any detectable neutrino emissions or very high energy gamma rays.

The study of this phenomenon, which had never been directly observed before, opens up many possibilities, especially a better understanding of the origin of the very heavy elements in the universe, and a completely new way to measure the rate of expansion of the universe.

The ensemble of these exceptional results was published on October 16, 2017 in a series of articles appearing in the journals Nature, Astrophysical Journal, and Physical Review Letters.