New scientific discovery stirs the scientific community
For the first time, scientists have measured the violent death spiral of two dense neutron stars via gravitational waves.
This new discovery from the LIGO-Virgo collaboration comes weeks after the detection of gravitational waves won the 2017 Nobel Prize in Physics.
The event on August 17, 2017 was detected by about 70 ground and space-based observatories, marking the first time a cosmic event has been viewed in both gravitational waves and light.
Researchers say that the event they observed occurred about 130 million years ago as two neutron stars were in their final moments of orbiting each other.
As the stars spiraled closer together, they distorted the surrounding space-time, giving off energy in the form of gravitational waves before smashing into each other.
As they collided, they emitted a “fireball” of gamma rays; the new observations show that heavy elements such as lead, and gold are created during these collisions.
Professor David Wiltshire, Department of Physics & Astronomy, University of Canterbury said that the first discovery of gravitational waves from the merger of two neutron stars is an historic event.
“It is every bit as exciting as the first discovery of gravitational waves from merging black holes! Since this involves neutron stars that radiate light, for the first time we can also see what is going on in an extreme astronomical event that shakes up space-time,” he said.
“This merger has been followed up by satellites and telescopes all over the planet. In one hit it solves a cosmic mystery – the origin of short duration gamma-ray bursts. We have seen flashes of gamma rays like the ones that the Fermi satellite saw from this event for decades without knowing what they are. Now we know.”
One further cosmic gravitational wave first still awaits us: the merger of a black hole with a neutron star. Such events should also give out light and other electromagnetic waves. And they will be different to anything we have seen yet. When that happens, it will again open up completely new frontiers for 21st-century astronomy.”
Detecting gravitational waves
Dr J J Eldridge, Astrophysicist at University of Auckland said that the event was awaited by many astrophysicists since LIGO (The Laser Interferometer Gravitational-Wave Observatory) made the first detection of gravitational waves in 2015.
“This time we did not just detect the gravitational waves from two merging neutron stars, but have also seen the associated gamma-rays, optical light and radio emission from the possibly black holes and from the two exploding stars,” he said.
“This new discovery shows again the importance of LIGO and VIRGO’s work over decades. The refinement of their highly sensitive work allows us to be able to detect these gravitational waves. But we do not even know the full story yet. The observations are ongoing and only in the coming months and years will we really begin to fully understand how exciting this object is. The fact that we have so much information from so many different sources will allow us to piece together in a way we have never been able to before. It would take more time and effort,” he added.
Dawn of New Era
Associate Professor Renate Meyer, Department of Statistics, University of Auckland said that with the recent stunning detection of a binary neutron star merger, Advanced LIGO/Virgo have ushered in an exciting new era of astrophysics that highlights the importance of effective collaborations between gravitational wave observatories and other electromagnetic telescopes such as Fermi GBM, INTEGRAL, Chandra, Hubble, Swope and DECam.
“Arguably, this detection and its follow-up observations of gamma rays, X-rays, ultraviolet, optical, infrared, and radio waves have an even higher significance for fundamental physics than the very first detection of gravitational waves in September 2015,” he said.
Editor’s Note: The above article is a redaction of a longer article that appeared in our Web Edition (www.indiannewslink.co.nz) on October 17, 2017. It can be found under our Archives.
About GW+EM Observatories Map
A map of the approximately 70 light-based observatories detected the gravitational-wave event called GW170817. On August 17, the LIGO and Virgo detectors spotted gravitational waves from two colliding neutron stars. Light-based telescopes around the globe observed the aftermath of the collision in the hours, days, and weeks following. They helped pinpoint the location of the neutron stars and identified signs of heavy elements, such as gold, in the collision’s ejected material.
Stars collisions create gold–GW EM Observatories (Map Credit LIGO-Virgo)