Japan's gravity wave tracking observation team J-GEM observes the gravity wave source "GW170817" observed by the gravity wave telescopes "LIGO" (USA) and "Virgo" (Europe), and the visible and infrared compatible celestial bodies of the gravity wave source. For the first time, I succeeded in tracking the change in brightness over time.The observation team consists of Hiroshima University, National Astronomical Observatory, Konan University, Kagoshima University, Nagoya University, and the University of Tokyo.
The gravitational wave predicted by Einstein in 1916 is a phenomenon in which the distortion of space due to gravity is transmitted at the speed of light. It was first directly observed by LIGO in 2015, and the 2017 Nobel Physics Award was awarded for this achievement.However, it was unclear which celestial body emitted it only by gravitational wave observation.
Neutron stars are high-density objects with a radius of about 10 kilometers (density is 1 billion tons per cubic centimeter), and unlike the case of black hole coalescence, when neutron stars coalesce, electromagnetic radiation of various wavelengths was expected. ..
On August 2017, 8, the LIGO / Virgo joint team observed gravitational waves due to neutron star mergers.Immediately passed on to more than 17 observatories around the world. Eleven hours later, several telescopes discovered a celestial body (SSS70a) corresponding to gravitational waves.
Approximately 17 hours after gravity wave detection, Hawaii's Subaru Telescope (National Astronomical Observatory), New Zealand's MOA-II Telescope (Nagoya University, Osaka University) and B & C Telescope (Canterbury University), South Africa's IRSF Telescope (Nagoya University, Kagoshima University), We carried out optical infrared tracking observations with a group of telescopes in Japan, and succeeded in tracking the dimming of near infrared rays for 15 consecutive days.
This observation result is attributed to the electromagnetic radiation phenomenon "Kilonova" accompanied by the "r process", which is one of the processes for synthesizing elements heavier than iron (gold, platinum, rare earth, etc.). It is taken as a step.
