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Astronomers have released the biggest catalog of gravitational waves ever assembled, nearly doubling what scientists knew about these ripples in spacetime from just one batch of new data. The LIGO, Virgo, and KAGRA Collaboration, known collectively as LVK, announced the catalog, named GWTC-5.0, adding 161 newly confirmed events detected between April 2024 and January 2025. That pushes the total number of gravitational wave signals recorded since the first detection in 2015 to 390, a milestone the collaboration describes as ushering in a new era of statistical astronomy.
Gravitational waves are ripples in the fabric of spacetime, predicted by Einstein and first directly detected in 2015, produced when massive objects like black holes or neutron stars spiral into each other and collide. Unlike light, these waves pass largely unimpeded through gas and dust, letting instruments on Earth detect collisions that happened billions of light years away and that no telescope could ever see directly. LIGO’s twin detectors in the United States, joined by Virgo in Europe and KAGRA in Japan, listen for the tiny stretching and squeezing of space that these collisions cause, changes thousands of times smaller than the width of a proton.
The scale of this release matters because bigger catalogs let physicists do something individual detections cannot, which is study black holes as a population rather than as isolated curiosities. Leo Tsukada, a researcher at the University of Nevada Las Vegas involved in the analysis, said the growing collection of signals enables population studies and tests of general relativity with what he called unprecedented precision. With Virgo’s data helping triangulate where signals came from, the team achieved the most precise sky localization yet for a gravitational wave source, an event called GW240615, pinned down to just six square degrees of sky, a black hole merger involving objects of roughly 26 and 30 solar masses that occurred more than 3 billion light years away.
The catalog also contains the clearest gravitational wave signal ever recorded, with a signal to noise ratio of 76.9. That event, GW250114, came from two black holes of nearly identical mass merging more than a billion light years away and had already made headlines when it was used to confirm predictions from general relativity and Stephen Hawking’s black hole area theorem. Perhaps the most intriguing find involves two separate mergers, cataloged as GW241011 and GW241110, whose black holes show spin patterns suggesting they themselves formed from earlier mergers, what physicists call second generation black holes. Finding and confirming such objects helps researchers understand the dense, crowded environments, like star clusters, where black holes can collide repeatedly over cosmic time.
Beyond black hole demographics, the larger dataset is sharpening one of cosmology’s most stubborn puzzles. Hsin-Yu Chen of the University of Texas at Austin said the expanded set of gravitational wave sources produced an independent measurement of the Hubble constant, the number describing how fast the universe is expanding, with about 25 percent better precision than earlier gravitational wave estimates. That measurement matters because different techniques for calculating the Hubble constant keep disagreeing with each other, a discrepancy known as the Hubble tension that, if it persists, could mean something is missing from current models of the cosmos.
The fourth observing run that produced this catalog, run jointly by the NSF funded LIGO facilities, the European Gravitational Observatory’s Virgo detector, and Japan’s KAGRA instrument, now accounts for roughly three quarters of every gravitational wave detection made since 2015, a reflection of how much more sensitive the detectors have become after successive rounds of upgrades. There is still more data from the current run left to process, with the final portion expected in December, meaning this catalog is a milestone rather than a finish line. As the detector network keeps expanding and improving, physicists expect the pace of discovery to keep accelerating, turning what began as a handful of exotic detections into a steady, structured census of the universe’s most violent collisions.
Source: LIGO Laboratory / Caltech (GWTC-5.0 release) and the LIGO-Virgo-KAGRA Collaboration. Credit: LIGO / Virgo / KAGRA.