The 4th Observing Run: Astrophysical Science Results

The O4 LIGO-Virgo-KAGRA observing run is pushing the gravitational-wave window onto the Universe open wider than ever. O4 is still ongoing, and currently planned to run into June 2025. The number of new significant candidate events distributed via low-latency alerts had already outstripped the O1-O3 total by mid-2024, and keeps growing. Detections of compact binary coalescences continue to bring new insights into the astrophysics and evolutionary history of such systems, and to yield increasingly stringent results in probing cosmology and fundamental physics. With improved detector sensitivity, many new types of gravitational-wave signals and their sources are also within realistic reach of detection. This talk will summarize the highlights of O4 observational results so far.