GW250114 reveals signatures of post-merger black-hole horizon

Nature, Published online: 24 June 2026; doi:10.1038/s41586-026-10696-0

The observation of a direct wave after the merger of two black holes reveals signatures associated with the remnant black-hole horizon, establishing an observational channel to directly measure frame-dragging effects in black-hole ergospheres and probe the horizon surface gravity.