Stellar occultations by small bodies - Diffraction effects

In recent years, stellar occultations have been a powerful tool in the study of small bodies of the solar system (e.g., rings, satellites, asteroids). Diffraction effects have to be taken into account in order to interpret light curves. The authors develop theoretical models, from the Fresnel-Kirchhoff diffraction theory, of occultations by semitransparent strips and opaque elliptical disks, and give explicit methods for computing them. They discuss the theoretical implications of diffraction during stellar occultations and use their own models to distinguish the dips that are artifacts from those that can correspond to real planetary objects. The authors apply these considerations to some observations of Uranus' rings and Neptune's arcs.