LIGO and VIRGO together for the first time saw the merging of black holes

© Photo : Michael Koppitz / aetac the artist imagined merging black holes and they produce gravitational wavesLIGO and VIRGO together for the first time saw the merging of black holes© Photo : Michael Koppitz / aei

Gravitational Observatory LIGO and VIRGO for the first time found a burst of gravitational waves generated by merging black holes and localized the source to one of the galaxies in the constellation Hours, told participants VIRGO and LIGO collaborations, speaking at a press briefing at a meeting of Ministers «the Big seven» in Turin, Italy.

«Association of LIGO and VIRGO not only increased the accuracy of localization of sources of gravitational waves 20 times, but also allowed us to begin to search for traces of the objects that generate gravitational waves, and other types of radiation. Today, we truly have entered the era of full-fledged gravitational astronomy,» said David shoemaker (David Shoemaker), head of the LIGO collaboration.

In search of the folds of space-time

The gravitational wave detector LIGO has been built in 2002 on projects and plans that have been developed by a Kip Thorne, Rainer Weiss and Ronald Drever in the late 80’s of the last century. In the first stage of its work, which lasted 8 years, LIGO has failed to detect the «Einstein» fluctuations in space-time, after which the detector was disabled and the next 4 years, scientists have spent on upgrading it and increasing sensitivity.

These efforts were justified – in September 2015, in fact, immediately after switching on the upgraded LIGO, scientists detected a burst of gravitational waves generated by merging black holes with total mass in 53 of the Sun. Subsequently, LIGO has recorded three more burst of gravitational waves, only one of which was officially recognized by the scientific community.

Scientists don’t know exactly where was located the sources of these gravitational waves is due to the fact that LIGO has two detectors, they only managed to allocate quite a narrow band in the night sky, where they could be these black holes. Inside her, despite her modest size, there are millions of galaxies, making the search for the «final product» of these mergers are actually useless.

In June this year, resumed its work the European «cousin» LIGO, a gravitational Observatory, VIRGO, constructed in the vicinity of the Italian Pisa in 2003. Work. was suspended in 2011, after which the engineering team of the Observatory held its deep modernization, bringing her sensitivity to the current level of LIGO.

Check all of the detectors VIRGO was completed by 1 August this year, and now the Observatory have launched a joint observation with two detectors LIGO. Its sensitivity is slightly lower than the American gravitational telescope, however, the resulting data allow us to solve two key scientific problems is to improve the quality and reliability of the signal received LIGO, and to determine the three-dimensional position of the source of gravitational waves.


The first results, scientists have made surprisingly quickly – already on 14 August, they were able to detect a surge GW170814 that occurred in a distant galaxy at a distance of 1.8 billion light years from Earth. As in the previous three cases, these waves were generated by unusually large black holes whose mass exceeds the sun at 30.5 and 25 times. During their merger about three the mass of the Sun has disappeared and was spent in the emission of gravitational waves.

The use of three detectors allowed scientists to significantly improve the accuracy of localization of the source of gravitational waves – galaxies, which are gave birth to their black holes, located in a small region of sky in the constellation Hours in the night sky of the southern hemisphere. In addition, the researchers plan to use these data to search for possible traces of this outbreak in radio and x-ray ranges.

One of the features of the European detector, as added yo van den brand (Jo van den Brand), head of the VIRGO collaboration, is that it is turned slightly to the other side compared to a couple of his American counterparts. This allows scientists to use them to measure the polarization of gravitational waves and test some basic assumptions of the theory of relativity, and the search of the parallel worlds.

Sensation in this case did not happen – a preliminary analysis of data collected by LIGO and VIRGO during this outbreak, shows that gravitational waves move through space and behave exactly as predicted by Einstein’s theory. In the future, when the sensitivity of LIGO and VIRGO will be improved, the researchers hope to find a definitive answer to this question.

As noted by the shoemaker, the LIGO detectors was disabled on 25 August in order to improve the accuracy of their work about two times. This «upgrade», he said, will expand the «horizon view» of the Observatory of approximately nine times, and will allow us to find traces of merging black holes almost every week.