Afterglow against galaxy brightness (IMAGE) Northwestern University Caption The box indicates where the neutron star merger (GW170817) and its afterglow occurred. The event's brightness is overwhelmed by the brightness of the galaxy (center). Credit Wen-fai Fong/Northwestern University Usage Restrictions None License Licensed content 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.