For the first time, astronomers have detected gravitational waves from a merging hypermassive neutron star. Gravitational waves were predicted by Albert Einstein in the general theory of relativity (1915). Waves are perturbations in space created by rapidly moving masses propagating from a particular source. When the waves reach the Earth, they seem incredibly weak, so the detection requires extremely sensitive instruments. Only in 2016, for the first time, scientists were able to capture gravitational waves and confirm their existence with the help of LIGO.
The graph shows data points from the LIGO gravity wave observatory. Before you is an event GW170817 in gravitational waves, created by the merger of two neutron stars. After the merger, the frequency of the gravitational wave decreases for a few seconds, indicating a combined object with a decreasing speed of rotation. After this event, the gravitational waves were found 6 more times. One of the events of GW170817 was the result of a merger of two neutron stars (stellar remnants). These objects appear after the stars are more massive than the Sun and exploding in the form of supernovae.
The graph displays the number of gamma rays in time, the initial peak of which is 1.7 seconds after the final merger of two neutron stars. A short gamma-ray burst lasts about 3 seconds.
Initially, scientists thought that GW170817 was the merging of two neutron stars into a black hole. The research team decided to test this using LIGO. Detailed analysis showed the detectors H1 and L1, divided into 3000 km with a burst that lasted 5 seconds. It is noteworthy that the surge began between the end of the initial surge of gravitational waves and the subsequent one from gamma rays. Low frequency indicates that before us is not a black hole, but a larger neutron star.