Dust grain distribution (thick line) measured along streamers B (bottom) and C (top). The conversion from β to grain size assumed ρ = 3000 kg m^-2. In both cases, the left end of the distribution is affected by the low S/N in the outskirt of the tail; the right end of the distribution was truncated when reaching the seeing disk of the nucleus. The narrow lines are linear fits to the distributions where they are not affected by the noise.