S6 (Sixth Observing Run of LIGO)

S6, or the Sixth Observing Run of LIGO, was a period from 2015 to 2016 when the Laser Interferometer Gravitational-Wave Observatory (LIGO) actively searched for gravitational waves—ripples in spacetime caused by massive cosmic events like merging black holes or neutron stars. It was part of a series of observation runs, improving detection sensitivity over time. Although S6 did not detect gravitational waves, it helped refine techniques and laid groundwork for future discoveries, culminating in the first confirmed detection in 2015 during a subsequent run.