Silhouette of the Flying Saucer disc seen against the ambient field at different wavelengths (green contours) plotted over the ALMA Band 7 millimetre dust disc image (colour map). From top to bottom, the disc silhouette is shown at 0.47 (HST F475W), 3.29 (NIRSpec), 7.7 (MIRI F770W), and 17.035 (MIRI/MRS) microns. Image and contours are rotated by 3°. The image is 5″ wide. In each panel, two sets of vertical tick marks denote the outer radii determined in the model for the small grain (235 a.u., green) and large grain (190 a.u., orange) populations, assuming a distance of 120 pc. The full width half maximum of the PSFs are shown as circles. At each wavelength, normalised vertical profiles are plotted to the right of the image. These are the projection across the full disc diameter for the ALMA image (dot-dashed, black) and cuts taken through the thickest point of the left lobe of the silhouette (red) and right lobe of the silhouette (blue). In the radial and vertical directions, the disc silhouette clearly has a greater extent than the continuum image.