LIGO Detects Another Gravitational Wave Event

June 2017


The LIGO Scientific Collaboration and the Virgo collaboration identify a third gravitational wave event in the data from the Advanced LIGO detectors.


On January 4, 2017 at 5:11:58 a.m. Eastern Standard Time, gravitational waves were detected by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA.


Gravitational waves carry information about their origins and about the nature of gravity that cannot otherwise be obtained, and physicists have concluded that the detected gravitational waves once again were produced during the final second of the merger of two black holes—31 and 19 times the mass of our sun—to produce a single, more massive spinning black hole that is 48 times the mass of the sun.


“This merger happened 3 billion years ago and it is the most distant of all confirmed events, which were detected by LIGO so far.” explained University of Florida Professor Sergey Klimenko, "Like the others, within a second, it turned the energy of about two solar masses into gravitational radiation.” The event was unambiguously identified by three independent search algorithms one of which, Coherent Waveburst, was developed at the University of Florida by a group of researchers led by Klimenko and fellow faculty member Professor Guenakh Mitselmakher.


"Advanced LIGO continues to reward us with observations of absolutely spectacular signals from the collisions of black holes. These highly energetic events are telling us about the nature of space and time," says David Tanner a University of Florida professor who, together with Professor Guido Mueller, has led development and construction of the LIGO Input Optics - one of the most complicated components of the LIGO detector.


The University of Florida has been an important part of the LIGO project since 1996 when UF Physics faculty took responsibility for the LIGO Input Optics and began development of Coherent Waveburst for LIGO data analysis. UF scientists led the design of key parts of the Advanced LIGO interferometer and continue to conduct research on materials and devices for future detectors. Over a period of seven years, UF together with the LIGO laboratory designed, built, installed and commissioned the input optics in time for the first science run of Advanced LIGO. It began in September 2015 with the discovery of gravitational waves from the LIGO GW150914 event, which was first detected by the UF search algorithm.


One of the most remarkable features of all gravitational wave detections so far is that the signals arise from binary black hole systems, with masses in a range that was completely unexpected. "This is very exciting", notes Professor Whiting from UF, "especially since, less than two years ago we did not know of their existence, and already we are now beginning to put constraints on models for their formation."


The LIGO Laboratory is funded by the NSF, and operated by Caltech and MIT, which conceived and built the Observatory. The NSF led in financial support for the Advanced LIGO project with funding organizations in Germany (MPG), the U.K. (STFC) and Australia (ARC) making significant commitments to the project. More than 1,000 scientists from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration. LIGO partners with the Virgo Collaboration, which is supported by Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare (INFN) and Nikhef, as well as Virgo's host institution, the European Gravitational Observatory, a consortium that includes 280 additional scientists throughout Europe. Additional partners are listed at:


LIGO research is carried out by the LIGO Scientific Collaboration (LSC), a group of more than 1000 scientists from universities around the United States and in 14 other countries. More than 90 universities and research institutes in the LSC develop detector technology and analyze data; approximately 250 students are strong contributing members of the collaboration. The LSC detector network includes the LIGO interferometers and the GEO600 detector.


Virgo research is carried out by the Virgo Collaboration, consisting of more than 250 physicists and engineers belonging to 19 different European research groups: 6 from Centre National de la Recherche Scientifique (CNRS) in France; 8 from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; 2 in The Netherlands with Nikhef; the Wigner RCP in Hungary; the POLGRAW group in Poland and the European Gravitational Observatory (EGO), the laboratory hosting the Virgo detector near Pisa in Italy.


The NSF leads in financial support for Advanced LIGO. Funding organizations in Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council, STFC) and Australia (Australian Research Council) also have made significant commitments to the project.


Several of the key technologies that made Advanced LIGO so much more sensitive have been developed and tested by the German UK GEO collaboration. Significant computer resources have been contributed by the AEI Hannover Atlas Cluster, the LIGO Laboratory, Syracuse University, and the University of Wisconsin-Milwaukee. Several universities designed, built, and tested key components for Advanced LIGO: The Australian National University, the University of Adelaide, the University of Florida, Stanford University, Columbia University of New York, and Louisiana State University. The GEO team includes scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI), Leibniz Universität Hannover, along with partners at the University of Glasgow, Cardiff University, the University of Birmingham, other universities in the United Kingdom, and the University of the Balearic Islands in Spain.