Multi-wavelength light curves (top panel), spectral energy distributions, and modelling during the prompt phase (bottom-left panel) and during the X-ray flares (bottom-right panel). The optical data points from D50 and the LAT upper limits are shown together with the best-fit spectral models. During the prompt phase (SP1, SP2), the extrapolated gamma-ray spectrum is consistent with the observed optical flux. During the X-ray flares (SP3–SP8), the optical flux was set as an upper limit for the joint fit.