Radial radiance profiles on the axis of the main jet. The horizontal line indicates the uncertainty level in the background subtraction and the vertical dotted lines indicate the minimum travel distance of dust for the first two exposures. For the 3rd image the much higher noise level is too high for useful analysis. Note that for the 3rd image (blue) acquired in VIS-610nm filter the brightness has been multiplied by p₃₇₅*f₃₇₅/p₆₁₀*f₆₁₀ to make the data comparable in terms of the dust cross section.