Concept-of-collision
Concept of collision of two neutron stars in space. Credit: ESA.

The European Space Agency’s (ESA) Integral satellite and Nasa’s Fermi probe have detected the emission of gravitational waves by the merger of two neutron stars for the first time.

The satellites recorded the two-second burst of gamma rays that was produced a few seconds after the merger of the neutron stars.

One of the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) experiment situated in the US also recorded the cosmic event.

Approximately 12h after the detections, scientists at several optical observatories, including the European Southern Observatory’s telescopes in Chile, located the optical afterglow near the core of NGC 4993 galaxy.

“Nothing like this had happened before: it was clearly the signature of a neutron star merger.”

ESA Integral project scientist Erik Kuulkers said: “This is a groundbreaking discovery, revealing for the first time gravitational waves and highly energetic light released by the same cosmic source.”

Scientists have previously confirmed the event of gamma-ray bursts, but they were the results of a collision between two black holes.

ESA Switzerland Integral Science Data Centre representative Volodymyr Savchenko said: “We had contributed to these earlier searches with Integral, looking for gamma- or X-ray emission and finding none, as expected from the vast majority of theories.

“Nothing like this had happened before: it was clearly the signature of a neutron star merger.

“This is the closest short gamma-ray burst detected among the ones for which we’ve measured the distance, and by far the dimmest one, nearly a million times less bright than average.”

After detecting the gamma-ray blast, Integral observed it for 5.5 days and had not detected any further rays.

ESA is currently working on the next generation of gravitational-wave experiments with Laser Interferometer Space Antenna (LISA), which is expected to be launched by 2034.