Watching black holes and neutron stars move across the sky

Precise position measurements of neutron stars and black holes—now possible with Gaia and other surveys—are exposing their true motions and natal histories. New data show that accreting binaries display mass-dependent velocities, and that neutron stars and black holes behave more alike than expected. Future surveys will catch supermassive black holes recoiling from gravitational wave kicks and spot them wandering through galaxy centers.