1. Radiation Pressure and Poynting-Robertson Drag for Small Spherical Particles

S. Soter, J. A. Burns, P. L. Lamy
1977 International Astronomical Union Colloquium  
A new heuristic derivation of the radiation pressure and Poynting-Robertson drag forces is presented for particles with general optical properties; previous derivations considered only perfectly absorbing materials. The equation of motion for a particle of mass m and geometrical cross-section A, moving with velocity v through a radiation field of energy flux F, is (to terms of order v/c)where r̂ is the radial unit vector, ṙ is the radial velocity, and c is the speed of light. The radiation
more » ... The radiation pressure efficiency factor Qprincludes both scattering and absorption, it is evaluated using Mie theory for small spherical particles with measured optical properties that are irradiated by the actual solar spectrum. Very small particles (<0.01 μm) are not substantially affected by radiation forces.
doi:10.1017/s0252921100070007 fatcat:o4nrdtlrijasxjjiepklldnqwa