Gaia Archive

The ''Gaia'' catalogues are star catalogues created using the results obtained by ''Gaia'' space telescope.

The catalogues are released in stages that will contain increasing amounts of information; the early releases also miss some stars, especially fainter stars located in dense star fields. Data from every data release can be accessed at the ''Gaia'' archive.

Initial Gaia Source List

The Initial Gaia Source List (IGSL) is a star catalogue of 1.2 billion objects created in support of the ''Gaia'' mission. The mission should have delivered a catalogue based entirely on its own data. For the first catalogue, Gaia DR1, a way was needed to be able to assign the observations to an object and to compare them with the objects from other star 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.

Attitude Star Catalog

The Attitude Star Catalog is a subset of the IGSL, required for the first approximation in the iterative evaluation of the ''Gaia'' data. A first version was created in 2013, a more refined version in April 2014. In total, the Attitude Star Catalog contains 8,173,331 entries with information on position, proper motion and magnitude. Starting with Gaia DR2, the Attitude Star Catalog was replaced with a new list generated from the Gaia Main Data Base (MDB), using the same criteria.

Gaia Spectrophotometric Standard Star Catalogue

IGSL contains a list of about 200 stars of different spectral classes and magnitudes needed for calibration of the photometric measurements. It is the result of the Gaia Spectrophotometric Standard Stars Survey (SPSS), a selection of stars using Earth-based data in advance of the Gaia mission. Previous cataloguess for calibrating magnitudes could not be used for the mission because many of these objects are too bright for ''Gaia'' to detect. It was anticipated that some of the stars selected may be previously unrecognized doubles or variable stars that would need to be deleted from the catalogue; for this reason the list contains more stars than necessary. For Gaia EDR3, a selection was made from more than 100,000 objects that were used for the calibration. These are well-observed objects selected according to Stetson Secondary Standards , but only Gaia data were used.

Gaia Initial Quasar Catalog

A list of quasars based on the Large Quasar Astrometric Catalog was prepared for IGSL. This in turn goes back to the Sloan Digital Sky Survey. From the more than one million objects, a selection of 150,000 quasars was made, which are in the region of Gaia's magnitude limit. The selected objects are already well observed and documented. In most cases, quasars are very far away, so that their proper motions and parallaxes are negligibly small.

Gaia Ecliptic Pole Catalogue

Gaia Ecliptic Pole Catalogue (GEPC) was created for measuring the poles. 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. It contains precise positions, UBV I photometry for the southern field and the corresponding magnitudes. The northern part was created with the Canada–France–Hawaii Telescope on Mauna Kea, Hawaii.

The GEPC v3.0 catalogue contains 612,946 objects from a field of one square degree each at the north and south poles. The north pole is relatively sparse and contains 164,468 objects, while the south pole is still in the region of the Large Magellanic Cloud and contains 448,478 objects. The GEPC data was needed right at the beginning of the mission for the initial calibration. The commissioning phase of the ''Gaia'' space probe ended on July 18, 2014. This was followed by a calibration phase of 28 days, during which the ecliptic poles were measured intensively. During this time, ''Gaia'' was operated in Ecliptic Poles Scan Law mode (EPSL), in which the two poles were measured twice during each revolution. The initial catalogue was used for Gaia DR1 to match ''Gaia''-found objects to previous star catalogues.

Gaia DR1

Gaia DR1, the first data release of the spacecraft ''Gaia'' mission, based on 14 months of observations made through September 2015, took place on 13 September 2016. The data release 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.

Gaia DR2

The second data release (DR2), which occurred on 25 April 2018, is based on 22 months of observations made between 25 July 2014 and 23 May 2016. It includes positions, parallaxes and proper motions for about 1.3 billion stars and positions of an additional 300 million stars, red and blue photometric data for about 1.1 billion stars and single colour photometry for an additional 400 million stars, and median radial velocities for about 7 million stars between magnitude 4 and 13. It also contains data for over 14,000 selected Solar System objects.

Gaia DR3

The first part of the third data release, EDR3 (Early Data Release 3), was released on 3 December 2020. It is based on 34 months of observations and consists of improved positions, parallaxes and proper motions of over 1.8 billion objects.

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). The final Gaia catalogue is expected to be released three years after the end of the Gaia mission.

''Gaia'' Archive

The ''Gaia'' Archive is a catalogue that contains positions and brightnesses for 1.7 billion stars, including distances and proper motions for more than 1.3 billion stars.

See also

* Data Processing and Analysis Consortium

References

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Astrometry
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Catalogue