Finding Planet Nine: a Monte Carlo approach

TL;DR

This paper employs a Monte Carlo method to simulate potential orbits of Planet Nine, identifying specific sky regions where it might be observed if it exists at aphelion, and discusses the robustness of ETNOs clustering.

Contribution

It introduces a Monte Carlo approach to statistically analyze the visibility and probable sky locations of Planet Nine based on its hypothesized orbital parameters.

Findings

Planet Nine could be located in one of four specific sky regions.

Two regions are compatible with an apsidal anti-alignment scenario.

The clustering of ETNO perihelia may not be entirely robust.

Abstract

Planet Nine is a hypothetical planet located well beyond Pluto that has been proposed in an attempt to explain the observed clustering in physical space of the perihelia of six extreme trans-Neptunian objects or ETNOs. The predicted approximate values of its orbital elements include a semimajor axis of 700 au, an eccentricity of 0.6, an inclination of 30 degrees, and an argument of perihelion of 150 degrees. Searching for this putative planet is already under way. Here, we use a Monte Carlo approach to create a synthetic population of Planet Nine orbits and study its visibility statistically in terms of various parameters and focusing on the aphelion configuration. Our analysis shows that, if Planet Nine exists and is at aphelion, it might be found projected against one out of four specific areas in the sky. Each area is linked to a particular value of the longitude of the ascending node and two of them are compatible with an apsidal anti-alignment scenario. In addition and after studying the current statistics of ETNOs, a cautionary note on the robustness of the perihelia clustering is presented.