Catching the first light from a gravitational wave event

Light and gravitational waves produced by the same event - a pair of neutron stars exploding - have been detected for the first time by a huge international collaboration involving UCL researchers. The outburst took place in a nearby galaxy called NGC 4993, located about 130 million light-years away in the direction of constellation Hydra. The simultaneous detection of light and gravitational waves has been described by scientists as 'like hearing thunder and seeing lightning for the very first time' and UCL researchers working on the Dark Energy Survey (DES) and Swift mission were some of the first to detect light produced by the stars exploding. A gravitational wave discovery was made on 17 August by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo collaborations as the event caused ripples in the Earth's space-time. This alerted observatories in space and on the ground to search for the source in the sky in the light from gamma-rays, through optical to radio waves. Just 1.7 seconds after the gravitational waves rushed past Earth, NASA's Fermi Gamma-ray Space Telescope caught high-energy light from an explosion associated with the event. Swift, Hubble and Chandra missions, along with ground-based observatories including the Blanco telescope in Chile used by DES, later captured the fading glow of the blast's expanding debris.