Sungrazing comets as solar probes and dust analyzers

The largest solar system bodies that approach the Sun closely are comets. Some graze the solar photosphere and are called sungrazers. All of the sungrazing comets undergo disproportionate brightening just before their perihelion passage. This phenomenon and the apparent transformation of the dust tail to a plasma tail have never been investigated thoroughly. Here we investigate fundamental concepts in order to open three new research areas for (1) determining the elemental composition of comet dust, (2) studying the physics of the corona, solar wind, and heliosphere, and (3) developing instruments for high-resolution spectral observations of these phenomena near the Sun. We developed the tools to calculate the correct illumination factors for surface elements and give an analytic solution for the transverse radiation flux when a comet nucleus is close to the Sun.