Overview

• Designated GW250114, the January 14, 2025 detection reached a signal‑to‑noise ratio of about 80, making it the clearest black‑hole merger signal to date.
• Analysis shows the remnant’s horizon area exceeded the combined pre‑merger areas (about 400,000 vs. 240,000 square kilometers), with outlets reporting confidence levels ranging from roughly 99.9% to 99.999%.
• Researchers isolated post‑merger overtones in the ringdown for the first time, providing strong evidence that the remnant behaves as a Kerr black hole characterized by mass and spin.
• The source involved two black holes of roughly 32 solar masses each at about 1.3 billion light‑years, producing a ~63‑solar‑mass remnant rotating on the order of 100 times per second.
• Improved sensitivity across the LIGO‑Virgo‑KAGRA network and decade‑long noise reductions enabled the precision tests reported in Physical Review Letters, with further gains expected from planned facilities like LIGO‑India, the Einstein Telescope, and Cosmic Explorer.