Emission mechanism of the optical/near-infrared excess is unresolved

Identify whether the optical/near-infrared excess observed between approximately 1 and 4 days post-burst in GRB220831A is produced by a flare from internal processes or by an internal plateau, by obtaining higher-cadence multi-band observations to resolve the component’s temporal evolution.

Background

The afterglow exhibits a steep post-break decay incompatible with standard forward-shock closure relations, suggesting an additional emission component. The authors model the excess with both a flare and an internal plateau, finding strong evidence for an extra component but insufficient data to discriminate between these mechanisms.

The lack of dense sampling between 1–4 days prevents definitive identification of the physical origin of the OIR excess.