On Physical Interpretation of the Poynting-Robertson Effect

TL;DR

This paper critiques and corrects previous claims about the Poynting-Robertson effect, providing a generalized equation of motion and clarifying misconceptions about its physical interpretation.

Contribution

It offers a corrected analysis of the Poynting-Robertson effect and generalizes the equation of motion for particles experiencing radiation drag.

Findings

Previous results by Srikanth (1999) are incorrect.

Provides a generalized equation of motion for the effect.

Clarifies misconceptions about isothermality and red-shift.

Abstract

Comments to the statements of Srikanth (1999) are presented. As for the standard definition of the Poynting-Robertson drag, the results of Srikanth (1999) are incorrect. Srikanth's statements about the isothermality condition and ``red-shift'' are also discussed. Srikanth's results are generalized for the most general case of the equation of motion when momentum loss per unit time is proportional to -v/c (higher orders are neglected), where v is (heliocentric) velocity of the particle, c is the speed of light.