Multifilter photometry of Solar System objects from the SkyMapper Southern Survey

Abstract

Context. The populations of small bodies of the Solar System (asteroids, comets, and Kuiper Belt objects) are used to constrain the origin and evolution of the Solar System. Their orbital distribution and composition distribution are both required to track the dynamical pathway from their formation regions to their current locations. Aims. We aim to increase the sample of Solar System objects (SSOs) that have multifilter photometry and compositional taxonomy. Methods. We searched for moving objects in the SkyMapper Southern Survey. We used the predicted SSO positions to extract photometry and astrometry from the SkyMapper frames. We then applied a suite of filters to clean the catalog from false-positive detections. We finally used 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 is higher than 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.