For the first time collision of two neutron stars has been detected by LIGO and simultaneously confirmed by lots of ground based telescope. The telescopes observed a faint glow of the gamma ray burst. The signal has been named GW170817.
And now it has become the first event which has been seen in Gravitational waves and light.
LIGO detected the signal of these two merging neutron stars on 17th August. But it was announced today as the paper regarding the discovery was published.
The signal was converted into sound waves. It’s really awesome that we can hear two neutron stars colliding. Really, I listened it over and over again until I was satisfied!
The deduction that the signal came from two colliding neutron stars was made by their mass and the chirp produced when they collide. Their mass was in between 1.1 to 1.6 solar masses and the chirp lasted for 100 seconds! So it was confirmed that these objects are much smaller that black holes.
So the neutron stars emitted gravitational waves which was detected for 100 seconds. About 2 seconds after this detection Gamma ray burst was observed. Because when they collided they emitted flash of visible light in the form of Gamma rays.
These neutrons stars are 130 million light years away from earth.
After its first detection on 17th August, astronomers observed the radiation coming out of the collision in different wavelengths for next few weeks .
This year’s Nobel prize was also awarded to the scientists who founded the idea of gravitational wave detector and thus the LIGO: “For the decisive contribution to the LIGO detector and the observation of gravitational waves.”
Here is the press release of the detection of the signal GW170817 by LIGO : ligo.org