This is not correct, the nature of gravitational waves emitted by the merging of two objects is different in its final stage, depending whether the objects form

This is not correct, the nature of gravitational waves emitted by the merging of two objects is different in its final stage, depending whether the objects form a black hole or not. Until a black hole is formed, the nature of the emission is the same for all objects (e.g. black holes or neutron stars), but if a black hole forms, the final emission (ringdown) is different. The first LIGO-Virgo events detected black hole mergers which resulted in black holes. The last LIGO-Virgo event detected two neutron star mergers. Unfortunately the sensitivity of the apparatus is not good enough to determine if the merge resulted in a black hole, or a neutron star based purely on gravitational wave measurements. However, we have secondary evidence[1] that the remnant was a black hole. [1] https://arxiv.org/abs/1710.05938 https://arxiv.org/abs/1710.05938