Trans-Neptunian Binary Mutual Events in the 2020s and 2030s

TL;DR

This paper develops probabilistic predictions for mutual events of trans-Neptunian binaries in the 2020s and 2030s, aiding observational planning and understanding of small bodies in the outer solar system.

Contribution

It introduces a Bayesian framework combined with high-precision orbit solutions to predict TNB mutual events, accounting for uncertainties and improving observability assessments.

Findings

Predicted mutual events for five TNB systems through the 2030s.

Generated distributions of event timing, duration, and depth with uncertainty estimates.

Highlighted the importance of rapid detection and follow-up observations.

Abstract

Mutual events of trans-Neptunian binaries (TNBs) provide rare opportunities to measure the physical and orbital properties of small bodies in the outer solar system. However, successful observations of these events have been limited by uncertain predictions. Here, we present probabilistic predictions of TNB mutual events occurring through the 2030s, using high-precision non-Keplerian orbit solutions from the Beyond Point Masses project combined with a Bayesian framework that propagates orbital and size uncertainties. Our methods generate distributions of event timing, duration, depth, and probability of occurrence, enabling direct assessment of observability. We provide predictions for five systems with ongoing or imminent mutual event seasons, including (38628) Huya, (58534) Logos-Zoe, (148780) Altjira, (469705) K\'ag\'ara and !H\~aunu, and (524366) 2001 XR$_{254}$. Preparing for upcoming events with long-baseline light curve monitoring is vital, as events may be difficult to distinguish from a regular rotational light curve. Rapid dissemination of event detections will benefit the entire community, allowing predictions to be updated, ensuring that these rare mutual event opportunities can be fully exploited.