Surface brightness profiles of the inner (left, from data set A) and outer (right, combined data sets A + B) disk of HD 100546. The black curve and the gray region represent the azimuthally averaged profile and standard deviation obtained after de-projecting the images by 42°. The profiles along the semimajor and semiminor axes are overplotted in color; they were obtained by averaging the radial profiles over a range of ±10° around the corresponding axis.