Multi-filter photometry of Solar System Objects from the SkyMapper Southern Survey

TL;DR

This study utilizes SkyMapper Southern Survey data to identify and classify over 117,000 Solar System objects based on multi-filter photometry, significantly expanding the available compositional information for small bodies.

Contribution

It provides a large, publicly available catalog of SSO photometry and taxonomy, improving the sample size and coverage of asteroid surface properties.

Findings

Catalog includes 880,528 observations of 205,515 SSOs.

Achieves 97% completeness down to V=18 mag.

Classifies 117,356 SSOs using Bus-DeMeo taxonomy.

Abstract

Context. The populations of small bodies of the Solar System (asteroids, comets, Kuiper Belt objects) are used to constrain the origin and evolution of the Solar System. Both their orbital distribution and composition distribution are required to track the dynamical pathway from their regions of formation to their current locations. Aims. We aim at increasing the sample of Solar System objects (SSOs) that have multi-filter photometry and compositional taxonomy. Methods. We search for moving objects in the SkyMapper Southern Survey. We use the predicted SSO positions to extract photometry and astrometry from the SkyMapper frames. We then apply a suite of filters to clean the catalog for false-positive detections. We finally use the near-simultaneous photometry to assign a taxonomic class to objects. Results. We release a catalog of 880,528 individual observations, consisting of 205,515 known and unique SSOs. The catalog completeness is estimated to be about 97% down to V=18 mag and the purity to be above 95% for known SSOs. The near-simultaneous photometry provides either three, two, or a single color that we use to classify 117,356 SSOs with a scheme consistent with the widely used Bus-DeMeo taxonomy. Conclusions. The present catalog contributes significantly to the sample of asteroids with known surface properties (about 40% of main-belt asteroids down to an absolute magnitude of 16). We will release more observations of SSOs with future SkyMapper data releases.