FIGARONET

The fast transient Universe has become a major field of study. It contains the most powerful explosive sources that have been discovered, Gamma-Ray Bursts. These ultrarelativistic sources are linked with other phenomena such as core-collapse supernovae or binary neutron star mergers. They are excellent candidates for the first detection of gravitational waves and neutrinos. GRBs have been observed from radio waves to several tens of GeV. The goal of this proposal is to build upon the European expertise and major instruments, such as the Advanced-Virgo gravitational interferometer, the SVOM GRB space mission, XMM-Newton, the ESO VLT, etc. in a strategic and coherent fashion. We propose building an international network to collaborate on developing the best strategies to follow-up these sources at all wavelengths, including all present and future instruments and multimessengers. Our goal is to optimize and to coordinate the studies of the data acquired, and to prepare the next generation science and instrumentation. We plan to write a proposal for a large European network, structuring the European community of high-energy transient and multimessenger astronomers, to play a major role on the international scene. This proposal will also result in a worldwide network, and a powerful tool for high-energy transient science, optimizing instrumentation and enhancing the collaboration between theoreticians and experimenters/observers.