Fits to the UVW1 (left panel) and U (right panel) light curves. Detections are shown as solid circles and non-detections are shown as open circles. The rise in UVW1 is fit with a straight line using the first three detections. The decays for both U and UVW1 are fit with exponential functions. For U, the data shown with squares were not included in the fit (see Sect. 3.1 for details). For UVW1, all detections (starting from the peak) were used in the fit. The inferred t₂ from the fit for UVW1 is 3.5 days, just before the cluster of data.