On August 17, 2017, scientists made the first direct observation of a merger between two neutron stars—the dense, collapsed cores that remain after large stars die in a supernova explosion. The merger is the first cosmological event observed in both gravitational waves—ripples in the fabric of spacetime—and the entire spectrum of light, from gamma rays to radio waves.
University of Maryland researchers from the Department of Physics and the Department of Astronomy played key roles in detecting both the gravitational and light signals of the historic event, and co-authored several research papers published on October 16, 2017.
Gravitational waves from the merger arrived first at the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Hanford, Washington, and Livingston, Louisiana, and the newly operational Virgo detector, located near Pisa, Italy. Less than two seconds later, the Gamma-ray Burst Monitor on NASA’s Fermi Gamma-ray Space Telescope detected a short burst of gamma rays.
A rapid analysis of these signals enabled the LIGO and Virgo teams to locate the signal in a region covering less than 0.1 percent of the total sky area as viewed from Earth. Astronomers around the globe then directed more than 70 space- and ground-based telescopes toward the event for follow-up observations.
For a full account of the observations, click here.