Reasons why this is important:
- It is the first simultaneous detection of a gravitational wave and electromagnetic signal (and the strongest GW signal yet). It spectacularly corroborates the reality of the GW detection technology and analysis. The progenitor has been unambiguously located in a (relatively) nearby galaxy, allowing a host of other telescopes to obtain detailed measurements.
- It shows that GWs travel at the speed of light, a further verification of Einstein’s General Relativity.
- It shows that most of the very heavy elements such as gold, platinum, osmium etc. are plausibly produced by merging neutron stars and constrains the rate of such mergers in the local universe.
- It shows that short gamma ray bursts – some of the most energetic explosions in the universe – can be caused by neutron star mergers.
- It is the closest detected short gamma ray burst (with a known distance). That the progenitor has also been characterised allows a closer investigation of the interesting physics underlying the ejection and jet mechanisms thought to be responsible for the gamma rays.
- It provides observational constraints on how matter behaves at extremely high densities, testing our understanding of fundamental physics to its limits – for example, the details of the gravitational wave signal moments before merger are diagnostic of the interior conditions of neutron stars at densities of ∼1018∼1018 kg/m33.
- It provides an independent way of measuring the expansion of the universe, because the distance to the GW source pops out of the analysis and can be compared with the redshift of the identified host galaxy. The result agrees with measurements made using the cosmic microwave background and the distance-redshift relation calibrated by other means, verifying our estimation of distances, at least in the local universe.
ESO Telescopes Observe First Light from Gravitational Wave Source
ESO’s fleet of telescopes in Chile have detected the first visible counterpart to a gravitational wave source. These historic observations suggest that this unique object is the result of the merger of two neutron stars. The cataclysmic aftermaths of this kind of merger — long-predicted events called kilonovae — disperse heavy elements such as gold and platinum throughout the Universe. This discovery, published in several papers in the journal Nature and elsewhere, also provides the strongest evidence yet that short-duration gamma-ray bursts are caused by mergers of neutron stars.
.. As night fell in Chile many telescopes peered at this patch of sky, searching for new sources. These included
- ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA) and VLT Survey Telescope (VST) at the Paranal Observatory, the
- Italian Rapid Eye Mount (REM) telescope at ESO’s La Silla Observatory, the
- LCO 0.4-meter telescope at Las Cumbres Observatory, and the
- American DECam at Cerro Tololo Inter-American Observatory.
- The Swope 1-metre telescope was the first to announce a new point of light.
It appeared very close to NGC 4993, a lenticular galaxy in the constellation of Hydra, and VISTA observations pinpointed this source at infrared wavelengths almost at the same time. As night marched west across the globe,
- the Hawaiian island telescopes Pan-STARRS and Subaru also picked it up and watched it evolve rapidly.
.. “ESO’s great strength is that it has a wide range of telescopes and instruments to tackle big and complex astronomical projects, and at short notice. We have entered a new era of multi-messenger astronomy!” concludes Andrew Levan, lead author of one of the papers.
How ‘Eureka’ Moments in Science Happen
From bathtubs to falling apples, find out what really drives some of the iconic tales of “light bulb” moments in science.
A falling apple prompts physicist Isaac Newton to formulate his laws of gravity. Greek polymath Archimedes takes a bath and figures out how to calculate volume and density. These are iconic “light bulb” moments in the history of science. Or, as Archimedes reputedly said when insight struck, Eureka!
Today, the flash of insight is measurable using brain scans, which show a part of the right hemisphere lights up at that moment. While Anna Marie Roos, a historian of science at the University of Lincoln, advises us to take some “eureka moments” with a grain of salt, she thinks they do have much to say about the creative process.
.. people love them because it simplifies things and takes away all the hard slogging. It’s an analogy everybody understands. Eureka stories are a compression of decades and decades of work into one inspirational moment. It’s like a parable.