2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4849Equation of motion for real dust particle under the action of electromagnetic radiation is more general than equation of motion corresponding to standardly used Poynting-Robertson effect (P-R effect). As a consequence, orbital evolution of particles may significantly differ from that corresponding to the P-R effect. The paper discusses recently published (Icarus, June 2002) derivation of equation of motion, which is in contradiction with known relativistically covariant formulation. The ``new'' derivation does not respect fundamental physical laws (law of conservation of energy, law of conservation of momentum) which must hold in any frame of reference. Application of the derived ``general'' equation of motion to the special case treated by Einstein in 1905 yields result which is not consistent with Einstein's result. Correct solution is presented.Astrophysicstext