The capture of interstellar dust: the pure electromagnetic radiation case

Possible capture of arbitrarily shaped interstellar dust due to the action of electromagnetic radiation and gravitational forces of the Sun is investigated. While earlier investigations have used the Poynting–Robertson effect as a representation of the electromagnetic radiation force, we also use generalized electromagnetic radiation force applicable both to spherical and non-spherical particles. It is shown that the capture depends not only dust particle size and chemical composition, but also on particle shape. Particles with effective radii less than approximately 0.2 μm are blown off from the Solar System due to action of radiation pressure. Large submicron and small micron-sized non-spherical particles are captured at much larger distances from the Sun than spherical particles. As a consequence, realistically shaped particles can survive in the Solar System, while spherical ones of the same size vanish (sublimate or hit the Sun).