Nonspherical dust grains in mean-motion orbital resonances

The effect of stellar electromagnetic radiation on the motion of arbitrarily shaped dust particles in mean-motion orbital resonances with planets is investigated. Giving a resonance and a value of parameter beta (the ratio between radiation pressure force and gravitational force of the central star), nonradial components of radiation pressure force are calculated when a given trajectory is prescribed. The found values of the nonradial components are in a good agreement with published detailed numerical simulations for a given nonspherical particle. Therefore nonspherical grains are present in mean-motion resonances with planets. Similarly, the difference between the motion of a real particle and the motion influenced by the Poynting-Robertson effect may be important.