NAC OSIRIS images (first column) for the eight spots reported in Table 1 with a zoom on the spot (second column). The images have been taken with F22 filter (at 649.2 nm). The arrows indicate the spots that have been analysed using boxes of 3 × 3 pixels. The measured I/F(α) of the bright spots are reported in red, while the surrounding area is reported in black (third column). The relative reflectance (normalized to F23 at 535 nm) of the indicated bright spot in red and the surrounding area in black are represented in the fourth column.