A new detection of gravitational waves has been confirmed. Although, the “new” we have to take it with tweezers.
Actually it is a less relevant detection and that was also eclipsed (never better said) by two other much more important and media: on the one hand related to the fusion of neutron stars ( GW170817 ) and on the other, the related with the collision, much more shocking than the current one, of another pair of black holes ( GW170814 ).
Curiously, this last one happened just a few weeks after the one that now occupies us.
The detection took place on June 8 and has received the name of GW170608. Let us remember briefly that these findings are baptized with the letters “GW”, followed by the date in American format (year-month-day). On this occasion it has been about the fusion of two black holes of 7 and 12 solar masses located a billion light years from our beloved planet Earth.
As in the other two mergers mentioned above, this has been another fruit of the successful LIGO-VIRGO collaboration, although in this case, and as we will now explain, only one interferometer was real and fully operational. Another “minor” reason for the delay in the dissemination of this discovery has been, as on other occasions, the duty of scientists to publish first in journals of the field and managed and reviewed by the scientific community.
The article in question is freely available and you just have to look at the list of authors to get an idea of how huge these types of scientific challenges are.
But as we were saying, there is a deeper reason that has influenced even more in the delay of the announcement of this detection. The cause has had to do with something, at least, witty. It turns out that the Hanford interferometer (in Washington) was being checked at the time of detection. This revision consisted of manually “shaking” the mirrors at known frequencies.
When the device was in ‘revision’ mode, the alarms did not jump when passing the wave GW170608, but they did in the twin interferometer located in Livingston (Louisiana). Specifically, the aforementioned wave modified the path of light in this location 7 milliseconds later, just as it takes the speed of light to cross the US from coast to coast.
Unfortunately, only with an interferometer (that of Livingston) it is not possible to affirm with rigor that the phenomenon occurred is due to a gravitational wave. It is necessary to give the confirmation of the second detector (Hanford’s, in maintenance at that precise moment).
However, all was not lost: a more rigorous analysis of the data recorded by the latter device, has allowed separating the signals of the gravitational wave from the “artificial” generated during the maintenance phase. After this analysis it has been possible to affirm beyond doubt, that in truth, on June 8, the Earth was once again shaken by the hungry guts of the cosmos.
At this time, both LIGO and VIRGO are off to undergo much more substantial improvements that improve their sensitivity. Meanwhile, scientists will continue to examine with magnifying glass the data collected during the past months with the aim of finding new events that would have gone unnoticed in the real-time warning system.