1.1.1 Introduction and overview

Author(s): Jos de Bruijne

This is the user documentation of Gaia Early Data Release 3 (Gaia EDR3; click here for the full pdf version of this documentation). This documentation, in combination with the Gaia EDR3 data processing papers published in the Special Issue of A&A, describes how the raw data collected by the Gaia spacecraft have been converted to the data products that form this release. Gaia Collaboration et al. (2020a) provides an overview of the contents of Gaia EDR3 and a guide for the use of the data while Gaia Collaboration et al. (2016b) describes the Gaia mission. Detailed guidelines for how to deal with parallaxes and astrometric data in general are given by Luri et al. (2018). Fabricius et al. (2021) describes the overall validation of the Gaia EDR3 data. The data itself, as well as services such as cross-matches (Marrese et al. 2021) and visualisation tools, are available from the Gaia Archive at https://archives.esac.esa.int/gaia. The Gaia EDR3 data model, with several modifications with respect to the Gaia DR2 version, is described in Chapter 13 of this documentation. Credit and citation instructions can be found here. The Gaia mission home page is https://www.cosmos.esa.int/gaia/. Further, detailed information on the Gaia mission, the spacecraft, its operations, the science data, its processing, and the validation of the processed products are described in this documentation.