How telescopes closed in on colliding neutron stars. Yellow contours show area of gamma ray burst detected by NASA's Fermi telescope. White contours show the area of gravitational wave signal detected by LIGO and Virgo observatories. Red dot shows the location of the object detected by the DLT40 survey telescope. On left, inset images from the DLT40 survey on July 27 and Aug. 17, 2017 show a transient object (DLT17ck).