Gamma-ray bursts under a new light: the TeV emission from GRB190114C seen by the MAGIC telescopes

Gamma-ray bursts (GRBs) are the most luminous sources of electromagnetic radiation known in the Universe. GRBs had been observed over a broad energy range from the radio band up to GeV gamma rays, but the TeV gamma-ray band had remained terra incognita for a long time. Thanks to the MAGIC telescopes, designed to catch the fast glimpses of the GRBs, the first ever clear detection in this band was achieved for GRB 190114C, a bright, long GRB. The TeV emission from GRB190114C belongs to a new energetic component, providing an energy output comparable at the one at lower energies. We will discuss the details of the observations by MAGIC and the accompanying multi-frequency measurements by more than 20 instruments, from radio to gamma- rays, and the inferences on the emission mechanisms. This historical, highly significant detection has followed an intriguing hint of TeV emission from GRB 160821B, a short GRB with an associated kilonova. This hint, if real, has potential multi-messenger implications on the detectability of gravitational wave alerts in high-energy gamma-rays.