Gaia Data Release 3

The Solar System survey

¹ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
e-mail: [email protected]
² Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium
³ University of Helsinki, Department of Physics, PO Box 64 00014 Helsinki, Finland
⁴ Finnish Geospatial Research Institute FGI, Geodeetinrinne 2, 02430 Masala, Finland
⁵ INAF – Osservatorio Astrofisico di Torino, via Osservatorio 20, 10025 Pino Torinese, TO, Italy
⁶ IMCCE, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Univ. Lille, 77 av. Denfert-Rochereau, 75014 Paris, France
⁷ Minor Planet Center – Center for Astrophysics, Harvard & Smithsonian, 60 Garden St., MS 15, Cambridge, MA, USA
⁸ CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
⁹ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
¹⁰ Institut UTINAM, CNRS-UMR 6213, Université Bourgogne Franche-Comté BP 1615, 25010 Besançon Cedex, France
¹¹ Thales Services for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
¹² Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB), Martí i Franquès 1, 08028 Barcelona, Spain
¹³ Telespazio for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
¹⁴ Lohrmann Observatory, Technische Universitt Dresden, Mommsenstraße 13, 01062 Dresden, Germany
¹⁵ UNESP – Sao Paulo State University, Grupo de Dinamica Orbital e Planetologia, 12516-410 Guaratingueta, SP, Brazil
¹⁶ AKKA for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France

Received: 15 April 2022
Accepted: 1 June 2022

Abstract

Context. The third data release by the Gaia mission of the European Space Agency (DR3) is the first release to provide the community with a large sample of observations for more than 150 thousand Solar System objects, including asteroids and natural planetary satellites. The release contains astrometry (over 23 million epochs) and photometry, along with average reflectance spectra of 60518 asteroids and osculating elements.

Aims. We present an overview of the procedures that have been implemented over several years of development and tests to process Solar System data at the level of accuracy that Gaia can reach. We illustrate the data properties and potential with some practical examples.

Methods. In order to allow the users of Gaia DR3 to best exploit the data, we explain the assumptions and approaches followed in the implementation of the data processing pipeline for Solar System processing, and their effects in terms of data filtering, optimisation, and performances. We then test the data quality by analysing post-fit residuals to adjusted orbits, the capacity of detecting subtle dynamical effects (wobbling due to satellites or shape and Yarkovsky acceleration), and to reproduce known properties of asteroid photometry (phase curves and rotational light curves).

Results. The DR3 astrometric accuracy is a clear improvement over the data published in DR2, which concerned a very limited sample of asteroids. The performance of the data reduction is met, and is illustrated by the capacity of detecting milliarcsecond-level wobbling of the asteroid photocentre that is due to satellite or shape effects and contributes to Yarkovsky effect measurements.

Conclusions. The third data release can in terms of data completeness and accuracy be considered the first full-scale realisation of the Solar System survey by Gaia.