Gravitational bending of light by planetary multipoles

TL;DR

This paper derives the gravitational bending of light caused by planetary multipoles, including mass, dipole, and quadrupole moments, and discusses the potential for future observations to detect these effects.

Contribution

It provides a detailed derivation of light deflection by planetary multipoles within linearized Einstein gravity, accounting for microarcsecond precision effects.

Findings

All relevant terms of order 1 microarcsecond are classified and parametrized.

Future optical and radio interferometers can detect Doppler modulation and multipole-induced light deflections.

Detection prospects are discussed for Jupiter and Saturn.

Abstract

General relativistic deflection of light by mass, dipole, and quadrupole moments of gravitational field of a moving massive planet in the Solar system is derived in the approximation of the linearized Einstein equations. All terms of order 1 microarcsecond are taken into account, parametrized, and classified in accordance with their physical origin. We discuss the observational capabilities of the near-future optical and radio interferometers for detecting the Doppler modulation of the radial deflection, and the dipolar and quadrupolar light-ray bendings by Jupiter and the Saturn.