Long Gamma-Ray Bursts (LGRBs), the most powerful events in the Universe, are generated by jets that emerge from dying massive stars. Highly beamed geometry and immense energy make jets promising gravitational wave (GW) sources. However, their sub-Hertz GW emission is outside of ground based GW detector (LIGO) frequency band. Using a 3D general-relativistic magnetohydrodynamic simulation of a dying star, we show that jets inflate a turbulent, energetic bubble-cocoon that emits strong quasi-spherical GW emission within the LIGO band, 0.1-0.6 kHz, over the characteristic jet activity timescale, 10-100 s. This is the first non-inspiral GW source detectable by LIGO out to hundreds of Mpc, with 0.1-10 detectable events expected during LIGO observing run O4. These GWs are likely accompanied by detectable energetic core-collapse supernova and cocoon electromagnetic emission, making jetted stellar explosions promising multi-messenger sources.
3D GRMHD simulation of jet-cocoon in a collapsing star