The universe is humming with ripples in spacetime: Scientists just doubled our catalog of black hole and neutron star collisions

The LIGO-Virgo-KAGRA collaboration has roughly doubled the catalog of known gravitational-wave events with the release of GWTC-4, a new collection of 128 sources gathered during the observatories' fourth observing run between May 2023 and January 2024. The new entries include some of the strangest collisions yet: unusually heavy black hole mergers, lopsided pairings, and systems with spins so high they may be the product of earlier merger chains.

GWTC-4 roughly doubles the catalog of known gravitational-wave events and adds a new batch of unusually massive, asymmetric, and fast-spinning mergers to study.

The appeal here is not just the number of detections, but what they unlock. Each new signal gives researchers another way to test general relativity, trace how black holes grow, and sort out which collisions happen in ordinary stellar evolution versus more chaotic environments. The catalog is getting bigger, but it is also getting weirder, and that is exactly why it is useful.