Gaia catalogues
For this purpose, a separate catalog of objects from several other catalogues was compiled, which roughly represents the state of knowledge of astronomy at the beginning of the Gaia mission.
[3] The Attitude Star Catalog is a subset of the IGSL, required for the first approximation in the iterative evaluation of the Gaia data.
In total, the Attitude Star Catalog contains 8,173,331 entries with information on position, proper motion and magnitude.
IGSL contains a list of about 200 stars of different spectral classes and magnitudes needed for calibration of the photometric measurements.
Previous catalogues for calibrating magnitudes could not be used for the mission because many of these objects are too bright for Gaia to detect.
The southern part of the catalogue was compiled from observations made with the MPG/ESO telescope at the Max Planck Institute for Astronomy in La Silla, Chile.
The GEPC v3.0 catalogue contains 612,946 objects from a field of one square degree each at the north and south poles.
[11][12] It includes "positions and magnitudes in a single photometric band for 1.1 billion stars using only Gaia data, positions, parallaxes and proper motions for more than 2 million stars" based on a combination of Gaia and Tycho-2 data for those objects in both catalogues, "light curves and characteristics for about 3000 variable stars, and positions and magnitudes for more than 2000 extragalactic sources used to define the celestial reference frame".
[22] A number of issues have been identified with the DR2 data, including small systematic errors in astrometry and significant contamination of radial velocity values in crowded star fields, which may affect some one percent of the radial velocity values.
[26][27] The full DR3, published on 13 June 2022, includes the EDR3 data plus Solar System data; variability information; results for non-single stars, for quasars, and for extended objects; astrophysical parameters; and a special data set, the Gaia Andromeda Photometric Survey (GAPS), providing a photometric time series for about 1 million sources located in a 5.5-degree radius field centered on the Andromeda galaxy.
[28][29] The release dates of EDR3 and DR3 were delayed by the effects of the COVID-19 pandemic on the Gaia Data Processing and Analysis Consortium.
[32] The full data release for the five-year nominal mission, DR4, will include full astrometric, photometric and radial-velocity catalogues, variable-star and non-single-star solutions, source classifications plus multiple astrophysical parameters for stars, unresolved binaries, galaxies and quasars, an exo-planet list and epoch and transit data for all sources.
