Three-Step Observation (image) Max-Planck-Gesellschaft Share Print E-Mail Caption Three-step observation: the first sign of the neutron-star merger on 17 August 2017 was a brief burst of gamma rays discovered by US satellite Fermi (above). Soon after, scientists from the LIGO-Virgo cooperation reported that their detectors had recorded the gravitational waves 1.7 seconds before the Fermi burst (middle). A little later, scientists reported that the burst was also observed with an instrument aboard the European satellite Integral. Credit NASA's Goddard Space Flight Center, Caltech/MIT/LIGO Lab and ESA Usage Restrictions Use of images is limited to editorial coverage of scientific topics relating to the activities of the Max Planck Society. Any kind of commercial use (including, in particular, the exploitation of images by means of sale or incorporation in image databases or image catalogues) as well as any promotional use/use for merchandise purposes, disclosure to third parties or granting of related rights to third parties is expressly not permitted. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.