Insolation maps for the time of each OSIRIS observation. Inset: total dust brightness and gas production rates, measured inthe full 3.1 km annulus, as functions of subsolar longitude. The green box encloses the insolation maps that correspond to the subsolar longitudes where an excess of measured water production was found, relative to a simple model. The red box frames the insolation maps that correspond to the subsolar longitudes where a minimum of dust and a maximum of water production were measured.