Predictions for Sparse Photometry of Jupiter-Family Comet Nuclei in the LSST Era

TL;DR

This study demonstrates that LSST's sparse photometric data can reliably determine the rotation periods and pole orientations of Jupiter-family comet nuclei, improving understanding of their physical properties.

Contribution

It introduces a simulation-based approach to assess LSST's potential for characterizing JFC nuclei, highlighting the effectiveness of convex lightcurve inversion with sparse data.

Findings

Rotation periods can be reliably constrained.

Pole orientations can be accurately determined.

Convex models improve phase function estimates.

Abstract

The Legacy Survey of Space and Time (LSST) at Vera C. Rubin Observatory will deliver high-quality, temporally-sparse observations of millions of Solar System objects on an unprecedented scale. Such datasets will likely enable the precise estimation of small body properties on a population-wide basis. In this work, we consider the possible applications of photometric data points from the LSST to the characterisation of Jupiter-family comet (JFC) nuclei. We simulate sparse-in-time lightcurve points with an LSST-like cadence for the orbit of a JFC between 2024-2033. Convex lightcurve inversion is used to assess whether the simulation input parameters can be accurately reproduced for a sample of nucleus rotation periods, pole orientations, activity onsets, shapes and sizes. We find that the rotation period and pole direction can be reliably constrained across all nucleus variants tested, and that the convex shape models, while limited in their ability to describe complex or bilobed nuclei, are effective for correcting sparse photometry for rotational modulation to improve estimates of nucleus phase functions. Based on this analysis, we anticipate that LSST photometry will significantly enhance our present understanding of the spin-state and phase function distributions of JFC nuclei.