A magnetic thrust action on small bodies orbiting a pulsar

TL;DR

This paper studies how electromagnetic forces from pulsar winds affect small orbiting bodies, finding significant orbital drift for kilometer-sized objects over thousands of years, but minimal impact on larger bodies or planets.

Contribution

It introduces a new analysis of Alfvén wing-induced forces on small bodies around pulsars, extending previous theories to relativistic stellar winds.

Findings

Alfvén wing currents exert force on orbiting bodies.

Significant orbital drift occurs for kilometer-sized bodies over 10,000 years.

Minimal influence on planets or bodies larger than 100 km.

Abstract

We investigate the electromagnetic interaction of a relativistic stellar wind with small bodies in orbit around the star. Based on our work on the theory of Alfv\'en wings to relativistic winds presented in a companion paper, we estimate the force exerted by the associated current system on orbiting bodies and evaluate the resulting orbital drift. This Alfv\'enic structure is found to have no significant influence on planets or smaller bodies orbiting a millisecond pulsar. %influence on the orbit of bodies around a millisecond pulsar. On the timescale of millions of years, it can however affect the orbit of bodies with a diameter of 100 kilometres around standard pulsars with a period $P \sim $1 s and a magnetic field $B \sim 10^{8}$ T. Kilometer-sized bodies experience drastic orbital changes on a timescale of $10^4$ years.