Merging stellar-mass binary black holes

The LIGO and Virgo detectors have directly observed gravitational waves from mergers of pairs stellar-mass black holes, along with a smaller number involving neutron stars. These observations raise the hope that compact object could be used as probe stellar binary evolution, perhaps dynamics. This colloquium-style article summarises existing observations, describes theoretical predictions for formation channels merging black-hole binaries their rates observable properties, presents some prospects gravitational-wave astronomy.