Riccardo Ciolfi

Two neutron stars whirl in their final dance. If their spin aligns with their orbital motion, the partners merge neatly, launching a narrow jet of superheated matter. If they spin in opposite directions, the dance breaks apart, scattering a thick shroud of debris.

Two neutron stars, ultra-dense remnants of massive stars, merge into one, and the space around them shudders: a gravitational wave is born, a ripple in the very fabric of spacetime. Almost simultaneously, a narrow stream of matter, the jet, erupts from the scene.