Vesicular dust particles – light scattering and radiation pressure

ABSTRACT We present a new model for irregular vesicular particles, featuring both open and closed porosity. The model can simulate particles with large vesicles, comparable in size to the wavelength of light. Calculations of light polarization indicate that such particles might be suitable candidates to represent some cometary dust particles. For sub-micron-sized dust, the radiation pressure exerted on these particles is found to be significantly higher than that exerted on porous particles of the same material, size, and overall porosity, but consisting only of small pores. It is demonstrated that the average vesicle size is relevant to characterize the motion of the porous particle in an environment with radiation pressure. In particular, pore size can be a key parameter in determining the location of the small porous particles in the comet’s dust tail. Depending on the material, the numerical model of vesicular particles could also be relevant for other areas of physics, such as volcanic ash.