Tag Archives: LIGO

LIGO Detects a Neutron Star Merger

New LIGO discovery is an astronomer’s dream come true.

On August 17, astronomers detected gravitational waves and a gamma-ray burst from two colliding neutron stars. National Science Foundation/LIGO/Sonoma State University/A. Simonnet

On August 17, Mother Nature delivered a gift to astronomers as precious as anything they could have imagined: gravitational waves from two neutron stars spiraling inward and merging, followed moments later by a burst of gamma rays from the same patch of sky. This cosmic double whammy was officially announced today after nearly two months of rumors. It proves a long-standing theory for an enigmatic class of cosmic cataclysms while heralding a revolutionary new era of multi-messenger astronomy.

The sequence of events started at 8:41 a.m. Eastern time when a train of gravitational waves started rolling through the Virgo detector near Pisa, Italy. The same waves rumbled through the LIGO detector in Livingston, Louisiana, just 22 milliseconds later, then the twin LIGO detector in Hanford, Washington, 3 milliseconds after that.

The LIGO and Virgo instruments detected a crescendo of waves for a whopping 100 seconds — much longer than previous detections. The duration, amplitude, and frequency of the waves had all the characteristics that theorists have expected for a binary system consisting of two neutron stars on a death spiral ending with coalescence. The two neutron stars had masses of about 1.5 and 1.1 solar masses, respectively. About 1 to 2 percent of that mass was likely ejected into space during the merger, which presumably resulted in a black hole of nearly 3 solar masses, although the LIGO data does not prove that a black hole formed. If a black hole indeed formed, it’s the lightest black hole yet known.

Gravitational Waves in the news

Gravitational wave researchers win Nobel Prize
Three American physicists have won the 2017 Nobel Prize in Physics for their contribution to detecting gravitational waves.
Rainer Weiss (left) from MIT, Barry Barish from Caltech, and Kip Thorn from Caltech all shared the 2017 Nobel Prize in Physics.

Yesterday, over a hundred years after Albert Einstein first predicted the existence of gravitational waves, three American physicists won the 2017 Nobel Prize for Physics for their “decisive contribution to the LIGO detector and the observation of gravitational waves.”

Half of this year’s prize went to Rainer Weiss from MIT for his work conceptualizing and constructing the Laser Interferometer Gravitational-wave Observatory (LIGO), while the other half of the prize was split between Kip Thorne and Barry Barish from Caltech, both co-founders of the LIGO/VIRGO Collaboration.


Scientists catch another gravitational wave, and they know where it came from

Last year, physicists made history by observing the first-ever gravitational wave. Their discovery confirmed Albert Einstein’s century-old theory of gravity and capped decades of effort to build an instrument sensitive enough to catch these ripples in spacetime.

Since then, researchers working at the government-funded Laser Interferometer Gravitational Wave Observatory (LIGO) — twin detectors in Louisiana and Washington State — have caught several more gravitational waves.