LIGO and Virgo Announce Four New Detections of Gravitational Waves • The observatories are also releasing their first catalog of gravitational-wave events 3/12/2018 VIDEO: LIGO Orrery. Computer calculations modeling the gravitational waves LIGO has observed to date and the black holes that emitted the waves. The image shows the horizons of the black holes above the corresponding gravitational wave. Credit: Teresita Ramirez / Geoffrey Lovelace / SXS Collaboration / LIGO Virgo Collaboration. • On