On 10/9/22, Fermi-GBM detected the brightest gamma-ray burst, GRB 221009A since its launch in 2008. Preliminary GBM data analysis shows this burst surpasses the previous record holder, GRB 130427A by an order of magnitude in terms of fluence and at least double the peak flux. The prompt emission is so strong that atmospheric disturbances in the ionosphere have been seen in radio observations. Over 30 observatories have followed up this GRB so far, including IXPE. The relative proximity of this GRB enabled extensive afterglow detections across the entire electromagnetic spectrum, from radio to TeV gamma rays, with the most energetic photon ever reported at 18TeV. Observations are still ongoing and this comprehensive dataset will enable an in-depth study of the physics of jet formation and evolution.
Observation reports to the General Coordinates Network (GCN) associated with GRB 221009A to-date: https://gcn.gsfc.nasa.gov/other/221009A.gcn3
