Bolometric light curve, blackbody temperature, and radius evolution. The luminosity (top panel) is plotted in a log-linear scale. The shaded regions indicate the time regions where constant colour was assumed for extrapolation purposes for some of the bands. There is a break in the temperature evolution (middle panel) around 10−20 days post-peak. This is when He II recombines and we see the emergence of He I in the spectra. The early expansion of the photosphere (bottom panel) is best described (green dashed line) with a constant velocity v ≈ 4000 km s⁻¹ (i.e. ∼0.014c), one of the fastest expansion velocities recorded in TDEs.