Gaia DR4 pre-release

In June 2026, to allow the scientific community to prepare for the upcoming Gaia Data Release 4, a sample release of a few Gaia Data Release 4 sources was released, along with a draft version of the Gaia data model.

Astrometric time series for 12 sources

The Gaia DR4 astrometric time series of 12 sources are released in advance of the full release. These include single sources of different magnitudes and parallaxes, quasi-stellar objects, and three non-single stars with previously published Gaia astrometric Keplerian orbit solutions. The sources were selected with the goal of providing the community with illustrative examples of Gaia DR4 epoch astrometry.

The table below lists the identifiers of these sources, their common name when available, the group they belong to, and an approximate magnitude and parallax. The groups were defined as follows:

• "parallax": sources with approximate parallaxes of 1 mas and G magnitudes of approximately 9, 14, and 19 mag;
• "magnitude": sources with approx. G magnitudes of 14 mag and approx. parallaxes of 1, 5, and 10 mas;
• "qso": Quasi-stellar objects from the Gaia DR3 Celestial Reference Frame (CRF3);
• "orbit": sources with significant astrometric orbital signatures.

​​​The data can be downloaded in XML format here

The data structure and the available fields are described in the epoch_astrometry section of the draft Gaia DR4 data model described below.

If you use these data in your research or otherwise, please follow these acknowledgement and citation instructions: https://gea.esac.esa.int/archive/documentation/GDR3/Miscellaneous/sec_credit_and_citation_instructions/ 

Open-source Python code to analyse these data is available from the Gaia source update page (or https://github.com/esa/gaia-supdate) and example Jupyter notebooks are available at https://github.com/esa/gaia-jupyter-notebooks/tree/main/data-release-4-tutorials and from https://github.com/esa/gaia-bhthree/tree/gaia-dr4-prerelease.

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Draft Gaia DR4 datamodel

The data structure and the available fields of all Gaia DR4 products listed at https://www.cosmos.esa.int/web/gaia/dr4 are described in the draft Gaia DR4 data model that is available as a single PDF at the link provided here.​​​​