GW150914 is the first gravitational wave signal ever detected and the first discovery of a binary of black holes, marking the beginning of Gravitational astronomy. This discovery was made by the “online” low-latency version of coherent WaveBurst: the original screenshot of GW150914 event can be found here.

GW150914 Press Release

Hanford
Livingston

Time-Frequency maps of GW150914: Hanford data (left) and Livingston data (right).