The third LIGO-Virgo observing run (O3) began in April 2019, and has since announced three gravitational-wave observations – the binary-neutron star merger GW190425, the binary-black-hole merger GW190412, and most recently GW190812, the merger of a 23-solar-masss black hole with a 2.6-solar-mass object, that could be either the lowest-mass black hole yet observed through gravitational-waves, or the highest-mass neutron star ever found. Measuring the properties of these sources, in particular the masses of the objects, relied on several theoretical signal models, including the family of phenomenological models that is tuned to fully general relativistic numerical simulations of black-hole binaries that are performed in this project.

Over the last year, the models have been upgraded to include subdominant harmonics (which were essential to the analysis of GW190412), and to treat black-hole—neutron-star systems (of which GW190812 may be one). O3 data continue to be analysed using these models, and a full catalogue of all confirmed observations will be published when it is complete.