Gravity Waves from Black Holes Observed August 14, 2017

Since the first detection of gravitational waves by the LIGO interferometers on September 14, 2015, the advanced Virgo interferometer has been added to the detection system. That addition was very valuable when another gravitational wave event was observed on August 14, 2017. It was described by the APS News as follows: "The signal, which was observed on August 14, 2017, comes from a merger of a black hole 30.5 times the mass of the sun with another black hole 25.3 times the mass of the sun. The event occurred 540 megaparsecs from Earth, or about 1.8 billion light years away. Because the gravitational wave detection network involves three detectors, the researchers have been able to narrow down the location of the signal source by a factor of nearly 20 compared with LIGO's previous detections."

"The signal was first detected by the LIGO detector in Louisiana, then 8 milliseconds later by the LIGO detector in Hanford, then 6 milliseconds after that, by the Virgo detector."