Observational Constraints on Planet Nine: Cassini Range Observations

TL;DR

This study uses Cassini spacecraft data to place observational constraints on the possible location, distance, and mass of an undiscovered Planet Nine in the outer solar system.

Contribution

It provides new constraints on Planet Nine's sky position, distance, and mass based on Cassini range observations, narrowing down its possible location.

Findings

Preferred region centered at (RA, Dec) = (40°, -15°)

Sky position constrained within approximately 20°

Significant limits on the mass and distance of Planet Nine

Abstract

We significantly constrain the sky position, distance, and mass of a possible additional, distant planet in the solar system by examining its influence on the distance between Earth and the Cassini Spacecraft. Our preferred region is approximately centered on (RA, Dec) = ($40\arcdeg$, $-15\arcdeg$), extending approximately 20 degrees in all directions.