PoyntingRobertson effect for a spherical source of radiation
Abstract
This paper considers the effects of radiation forces on a small material particle which is gravitationally orbiting a finite spherical source of radiation The radiation forces are computed exactly, and the orbital equations and time of fall into the source are solved to the first order. When the particle is close to the sphere, all radiation drag effects increase above those for a point source. In a firstorder relativistic theory, the angular and radial drag forces become equal at the surface of the sphere, and are eightthirds and fourthirds times their pointsource values, respectively. The orbital equations give secular decreases in angular momentum, eccentricity, and semimajor axis in terms of complete elliptic integrals of the first, second, and third kinds When the particle is far from the sphere, all expressions reduce to Robertson's values for a point source.
 Publication:

The Astrophysical Journal
 Pub Date:
 May 1962
 DOI:
 10.1086/147329
 Bibcode:
 1962ApJ...135..855G