Two articles published on the arXiv server show a catalog of gravitational wave events detected by the LIGO and Virgo collaborations and the inferred properties concerning the black hole pairs discovered in the mergers. So far, 7 events were announced but the analysis of the data led to the discovery of 4 more events of which one was detected by Virgo as well. Of the 11 now known, there’s the one that became famous because it was generated by two neutron stars that led to a kilonova while the other 10 were generated by black hole pairs.