On April 18, 2020, the LIGO Scientific Collaboration and the Virgo Collaboration announced the discovery of gravitational waves from a binary black hole merger, labeled GW190412. This is the first binary black hole detection with clear evidence for unequal-mass components.

Simulation of the binary black hole merger GW190412 This shows a numerical simulation of the inspiral and merger of a binary black-hole with asymmetric masses and orbital precession, consistent with the inferred parameters of the gravitational-wave event GW190412. One black hole is 3.5 times more massive than the other. The black hole spins lead to precession of the orbital plane of the binary. Still images from the simulation can be downloaded from this link.
[Credits: N. Fischer, H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetimes project]

Audio files simulating the waveform of a binary black hole merger with mass ratio 3.6:1 The audio is of a simulated waveform with frequency 25 times higher than GW190412 (to improve audibility). Although the frequency shift means the total mass is not equivalent to that of GW190412, the mass ratio, spins, and inclination angle are chosen to be consistent with the inferred parameters of that event. The first file above is for a waveform that does not include higher harmonics of the primary waves, while the second file does.
[Credits: Florian Wicke and Frank Ohme (AEI Hannover, Germany)]