GW250114: 10 years of gravitational-wave astronomy

On September 10, 2025, the LIGO-Virgo-KAGRA Collaboration announced the discovery of GW250114, the highest SNR (signal-to-noise) ratio event observed to date. This signal originated from the coalescence of two black holes with near-equal masses (34 and 32 solar masses) and low spins. The high SNR of this event allowed for the measurement of two quasinormal modes of the remnant black hole, confirmation of Hawking’s area theorem, and other precision tests of general relativity. Additional information can be found in the publications, companion papers, science summaries, and other resources below.

The announcement of GW250114 comes approximately 10 years since the discovery of GW150914, the first source directly detected with binary black holes. Both events have similar masses and distances. But thanks to 10 years of technological advances reducing instrumental noise, the GW250114 signal is dramatically clearer.

Gravitational-wave signals recorded by the LIGO Hanford detector almost ten years apart. The top shows data from LIGO’s first-ever detection of gravitational waves, an event called GW150914, captured in 2015. The bottom shows the signal known as GW250114, captured in 2025. Both events involve colliding black holes about 1.3 billion light-years away with masses between 30 to 40 times that of our Sun. The purple line shows the data, which are a combination of the signal plus background detector noise. The green line shows the best-fit prediction from general relativity for each signal. The much lower noise seen today is thanks to cutting-edge improvements made to the LIGO detectors that hush unwanted noise. [Image credit: LIGO/J. Tissino (GSSI)/R. Hurt (Caltech-IPAC)]

Publications & Documentation

GW250114 infographic. [credit: Lucy Reading-Ikkanda/Simons Foundation]
GW250114 factsheet. [credit: S. Khadkikar/Penn State]

Audio comparison of GW250114 and GW150914. The visualization illustrates each signal’s increasing frequency with time, producing a “chirp” sound. Each detection plays twice: at the original frequencies and then with a 30% increase in pitch (to make the chirp easier to hear). Brighter colors indicate a large signal-to-noise ratio. Both signals came from colliding black holes with similar masses. But notice how much quieter the background noise is behind GW250114 compared to GW150914, an indication of how LIGO’s sensitivity has dramatically improved over the past decade. [Credit: LIGO/Derek Davis (URI)]

Additional Images & Videos

Numerical relativity simulation of GW250114. The blue and white surface shows a two-dimensional slice of the gravitational waves spiraling outward as the black holes orbit one another. The observed gravitational-wave signal from GW250114 is shown in white at the bottom. For comparison, the gray line shows much noisier data from LIGO’s first gravitational-wave observation, GW150914. While the amplitudes of these signals are comparable, significant improvements in detector sensitivity over the past decade have vastly reduced the amount of noise present in GW250114 relative to GW150914. [Credit: Deborah Ferguson, Derek Davis, Rob Coyne (URI) / LIGO / MAYA Collaboration.
Simulation performed with NSF’s TACC Frontera supercomputer.]

Ten Years of LVK Discoveries. This chart plots discoveries made by the LVK network since LIGO’s first detection in 2015. Most are binary black hole mergers, but a handful are black hole-neutron star or neutron star-neutron star collisions. So far, during the current, fourth science run, the LVK detectors have spotted about 220 mergers, which more than doubles the number (90) found in the first three runs combined. Total masses of the initial objects are represented by size, while the signal strength is indicated by color. The plot demonstrates that over time, the gravitational-wave observatories are both finding more black holes and detecting them with higher signal-to-noise ratios, thanks to cutting-edge advancements made to the detectors. Note that the black hole detections in the latter half of the fourth run are grey and appear to be the same size because these data have not been released in full—with the exception of the event called GW250114. That event, the clearest signal heard by LIGO yet, appears as a bright, orange dot on the chart in the fourth run. [Image credit: LIGO/Caltech/MIT/R. Hurt (IPAC)]
A Cosmic Symphony Revealed. This artwork imagines the ultimate front-row seat for GW250114, a powerful collision between two black holes observed in gravitational waves by the US National Science Foundation LIGO. It depicts the view from one of the black holes as it spirals toward its cosmic partner. Ten years after LIGO’s landmark detection of gravitational waves, the observatory’s improved detectors allowed it to “hear” this celestial collision with unprecedented clarity. The gravitational-wave data enabled scientists to distinguish multiple subtle tones ringing out like a cosmic bell across the universe (imagined here as intertwining musical threads spiraling toward the center). Though only LIGO was online during GW250114, it now routinely operates as part of a network with other gravitational-wave detectors, including Europe’s Virgo and Japan’s KAGRA. [Image credit: Aurore Simonnet (SSU/EdEon)/LVK/URI.]

Visualization of a binary black hole merger consistent with the gravitational-wave event GW250114. The first part of the animation shows the inspiral and merger of the two black holes, with a representation of the gravitational waves emitted in the equatorial plane. A few milliseconds into the ringdown phase, the gravitational wave representation is separated into the two modes of the ringing remnant black hole that were identified in the GW250114 observation: the quadrupolar fundamental mode (labeled “First tone”) and its first overtone (“Second tone”). It also shows a predicted third tone (with a hexadecapolar pattern) that the data place limits on. [Credit: H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), K. Mitman (Cornell University)]

Comparing advances in astronomical observations across the past decade for both electromagnetic and gravitational-wave observatories. The first row compares observations of the galaxy cluster SMACS 0723 taken by the Hubble Space Telescope in 2017 (left) and the James Webb Space Telescope in 2022 (right). The second row compares observations of GW150914 by the LIGO gravitational-wave detectors in 2015 (left) with observations of GW250114 by the upgraded LIGO detectors in 2025 (right). Both cases illustrate the significant increase in signal resolution produced by technology enhancements.
In this artist’s depiction, two black holes collide and merge, releasing gravitational waves. These waves can be detected by the LIGO-Virgo-KAGRA detectors on Earth, allowing scientists to determine the mass and spin of the black holes. The clearest black hole merger signal yet, named GW250114, recorded by LIGO in January 2025, offers new insights into these mysterious cosmic giants. [Image credit: Maggie Chiang for Simons Foundation]