Understanding the astrophysical sources of gravitational wave signals in the Fourth Observing Run

Understanding the latest trove of gravitational wave detections

The fourth observing run is bringing new gravitational wave detections at a greater pace than has happened before. I'm laying the groundwork to help understand the astrophysical systems which created these signals, and allow scientists internationally to gain new insights into the Universe.

Project news

25 Aug 2025

GWTC-4.0: introducing 128 new gravitational waves

My team and I published GWTC-4.0 — identifying 128 new gravitational-wave events during LIGO's fourth observing run and more than doubling the all-time total to 218 detected collisions.

Codename: o4pe
Dates: 2023-09 – present
Status: Ongoing
About: The fourth observing run of the international network of gravitational wave detectors places us on the cusp of a new era for gravitational wave astronomy. Detectors have now reached very high levels of sensitivity, and as a result the number of detections which are made each month has increased well-beyond what was possible less than five years ago. The detection rate will continue to increase in the coming years as the detectors approach and reach their design sensitivity. While this presents many new avenues for research, the substantially increased number of signals pose a considerable challenge to analysts. The fourth observing run represents a unique opportunity to test the new techniques which I, and my colleagues internationally, have been developing to rise to this challenge, allowing events to be analysed in an automated manner. This will allow a much larger number of events to be analysed than has previously been possible while maintaining the very high levels of quality assosciated with the international gravitational wave community's results.