Gravitational Waves: Ripples In Space-Time - NASA Goddard - astrophysics

Notes by NASA Goddard:Gravitational waves are ripples in the fabric of spacetime.They are caused by some of the most violent and energetic events in the universe,including colliding black holes;merging neutron stars or white dwarf stars;the wobble of neutron stars that are not perfect spheres;and possibly even the remnants of gravitational radiation create by the birth of the universe.*Gravitational waves were predicted by Einstein's General Theory of Relativity,but weren't confirmed until 2017.The NASA/ESA Hubble Space Telescope was able to photograph the galactic source of the waves.This opens up a new era of multi-messenger astronomy.

Hubble’s Inside The Image: M87 Jet - NASA Goddard - astrophysics