Description
Gamma-ray bursts (GRBs) are the most energetic explosions in the Universe, yet the physics of
their prompt emission phase remains poorly constrained. Simultaneous optical observations during
the prompt γ-ray phase provide a unique and direct diagnostic of the jet structure, emission
mechanism, and outflow Lorentz factor. To date, only a handful of events have been captured in
optical light during the prompt phase; the most remarkable case, GRB 080319B, reached nakedeye
brightness (V ~ 5.3) and was serendipitously observed by the wide-field TORTORA camera,
revealing a two-component jet geometry and an extremely relativistic outflow. We discuss the observational
requirements and instrument strategies needed to systematically detect GRB prompt
optical emission, focusing on two complementary approaches: (i) wide-field, high-cadence imagers
capable of monitoring large sky areas without the need for rapid slewing, and (ii) SIFAP-like
fast-photometry instruments mounted on telescopes with fast-response capability, which are wellsuited
for long-duration events (T90 > 90 s) and ultra-long GRBs. By rescaling from GRB 080319B,
we show that O(1) detectable events per year are expected with existing or near-future Italian
facilities. The scientific return of each such detection —from sub-second variability to real-time
optical–γ correlation —would be transformative for our understanding of the central engine.