The LIGO Scientific Collaboration and the Virgo collaboration today announced the first joint detection of gravitational waves with both the LIGO and Virgo detectors.

This is the fourth announced detection of a binary black hole system, and the first significant gravitational-wave signal recorded by the Virgo detector, and highlights the scientific potential of a three-detector network of gravitational-wave detectors.

Physicists at The University of Texas Rio Grande Valley’s Center for Gravitational Wave Astronomy (CGWA) are credited with contributions to the series of gravitational wave discoveries.

CGWA is housed at UTRGV and has been a member of the LIGO Scientific Collaboration since 1998. It is funded in part with grants from the National Aeronautic Space Administration and the National Science Foundation.

Dr. Mario Díaz, director of CGWA, said this discovery is yet another milestone in the history of gravitational wave astronomy.

“In the future, the shrinking of the probable area of localization of a gravitational wave source will it make easier for astronomers to find an electromagnetic counterpart, if that exists,” he said.


The three-detector observation occurred at 10:30:43 UTC on Aug. 14, 2017. The two Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, and funded by the National Science Foundation, and the Virgo detector, located near Pisa, Italy, detected a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes.

A paper about the event, known as GW170814, has been accepted for publication in the Physical Review Letters journal

The detected gravitational waves – ripples in space and time – were emitted during the final moments of the merger of two black holes with masses about 31 and 25 times the mass of the sun and located about 1.8 billion light-years away.

The newly produced spinning black hole has about 53 times the mass of our sun, which means that about three solar masses were converted into gravitational-wave energy during the coalescence.

“Little more than a year and a half ago, NSF announced that its Laser Gravitational Wave Observatory had made the first-ever detection of gravitational waves resulting from the collision of two black holes in a galaxy a billion light-years away,” said France Córdova, NSF director. “Today, we are delighted to announce the first discovery made in partnership between the Virgo Gravitational-Wave Observatory and the LIGO Scientific Collaboration – the first time a gravitational-wave detection was observed by these observatories, located thousands of miles apart.

“This is an exciting milestone in the growing international scientific effort to unlock the extraordinary mysteries of our universe,” Córdova said.

The Virgo detector joined the LIGO second observational run, O2, on Aug. 1, 2017, at

10:00 UTC. The real-time detection on Aug. 14 was triggered with data from all three LIGO and Virgo instruments. Virgo is, at present, less sensitive than LIGO, but two independent search algorithms based on all the information available from the three detectors demonstrated the evidence of a signal in the Virgo data, as well.