A luminous precursor in the extremely bright GRB 230307A

S. Dichiara, D. Tsang, E. Troja +3

GRB 230307A is an extremely bright long duration GRB with an observed gamma-ray fluence of $\gtrsim$3$\times$10${}^{-3}$ erg cm${}^{-2}$ (10-1000 keV), second only to GRB 221009A. Desp…