Measuring the mass of solar system planets using pulsar timing

TL;DR

This paper demonstrates that pulsar timing can be used to measure the masses of solar system planets with high precision, offering an alternative method to spacecraft observations and improving existing mass estimates.

Contribution

The study introduces a pulsar timing method to determine planetary system masses, achieving comparable or better accuracy than spacecraft data for some planets.

Findings

Masses of planets from Mercury to Saturn were measured using pulsar timing.

The Jovian system mass was determined with higher accuracy than previous spacecraft measurements.

Pulsar timing provides a viable alternative for planetary mass estimation.

Abstract

High-precision pulsar timing relies on a solar-system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet's orbital motion about the Sun. By using an array of pulsars (PSRs J0437-4715, J1744-1134, J1857+0943, J1909-3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best-known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2)E-4 Msun, being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurate measurements for individual solar system bodies, the pulsar technique is sensitive to planetary system masses and has the potential to provide the most accurate values of these masses for some planets.