Average brightness profile of the plume as a function of angular displacement along the spiral model locus. Data for our three filter bandpasses are given (line types indicated in the inset), together with a profile extracted from the numerical radiative transfer simulations of HMSK04 specific to our CH4 filter in the K band. Data for H and PAHCS are terminated shortly after the first full turn, at which point the signal‐to‐noise ratio in the images is insufficient to discern real structure from noise. For convenience, intervals of one and two complete revolutions are marked.