Gaia Data Release 4 (Gaia DR4)

The original Gaia DR4 data will become available from the Gaia ESA Archive. The expected content of Gaia DR4, pending certain processing and validation activities, is described here and summarised in this table.

Significant changes compared to previous Gaia data releases

Gaia DR4 is different from previous data releases in several ways:

Number and data volume of tables and other products

Gaia DR4 will contain a large number and diversity of data products. Lower-level data such as the individual observations underlying the source-level catalogue parameters will be released as well. Consequently, the total data volume of Gaia DR4 is approximately 500 TB with the largest fraction associated to the lower-level products. The total data volume of Gaia DR3 is 10 TB.

Content of the main source catalogues

In contrast to previous releases, data will be published for all processed sources, which amount to some 2.7 billion sources in total.

The gaia_source table in Gaia DR4 contains a high-quality subset of about 2 billion of these sources that are considered to have both high-quality astrometry and photometry. With respect to previous data releases, the parameters in this table are now consolidated from several different processing modules such that the best-suited model has been applied for a given source (e.g., a binary-star model instead of the default single-star model as was the case in Gaia DR3).

The  gaia_source table in Gaia DR4 is complemented by the following four tables that contain the results from the dedicated processing pipelines for all 2.7 billion sources:

  • all_source_astrometry: Results for all sources from the core astrometry pipeline
  • all_source_photometry: Results for all sources from the core photometry pipeline
  • all_source_rvs: Results for all sources from the core spectroscopy pipeline
  • all_source_flags: Compiles a selection of flags for each source published in the Gaia catalogue. 
     

Summary of expected tables in the Gaia DR4 archive

The columns of the table below have the following meaning:

  • Id: Identifier that will eventually map to the corresponding section in the data model documentation.
  • Data model chapter: Indicates the name of the data model chapter. The Gaia DR4 draft data model will be published in advance of the data release.
  • Gaia Archive Table Name: Indicates the table name in the Gaia ESA Archive.
  • Description: Description of the data set.
  • Category: Helps to distinguish between the different data sets.
  • New in DR4: Inidcates if the type of data was already published with Gaia DR3 or not. All data published with Gaia DR4 will be new, but some data product types have not been published before. These are indicated with "NEW". "NEW in Archive" marks products that were published elsewhere, e.g., on Cosmos, in previous releases.
  • Data level: Indicative data level of the product. Level 1 (DL1) corresponds to image data, i.e., CCD pixel/sample values. Level 2 (DL2) corresponds to epoch data, i.e., time-resolved processing results usually per CCD transit. Level 3 (DL3) corresponds to source-level data with summary results per celestial source. Level 4 (DL4) corresponds to derived quantities that incorporate astrophysical models and priors.
  • Label: Helps to distinguish between the different data sets.
The content of this table is under development and changes can be expected. Last update: 27 March 2025.

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Id Data Model Chapter Gaia Archive Table Name Description Category New in DR4 Data level Label
01.01 Main source catalogues gaia_source Sources considered to have both high quality astrometry and photometry. In contrast to previous data releases, the parameters in this table are consolidated from several different processing modules. Main   DL3 General
01.03 Main source catalogues all_source_astrometry Astrometric parameters obtained for all sources (except those in crowded_field_source and gaia_source_environment). Main NEW DL3 Astrometry
03.01 Crowded fields crowded_field_source Sources created with the crowded-field image analysis pipeline. Main   DL3 General
01.02 Main source catalogues gaia_source_environment Astrometry, photometry, and related information for sources detected by the SEAPipe processing in the surrounding of sources in the main Gaia source catalogue. Main NEW DL3 General
01.07 Main source catalogues bright_source_astrometry Astrometric parameters of 48 of the 51 brightest stellar sources in the sky, obtained using a special observation mode and special data processing methods. Main NEW DL3 Astrometry
07.0N Non-single stars tables optical_pair Optical Pairs / chance alignment of spatially close sources Main NEW DL3 Astrometry
09.01 Reference frame frame_rotator_source Sources used for the reference frame alignment and rotation. Main   DL3 Reference Frame
09.0N Reference frame agn_cross_id Sources that define the Gaia Celestial Reference Frame (CRF). Main   DL3 Reference Frame
03.05 Crowded fields crowded_field_image_summary Metadata for crowded field images published as FITS files. Main NEW DL1 Image
01.04 Main source catalogues all_source_photometry Photometric parameters obtained for all sources (except those in crowded_field_source and gaia_source_environment). Main NEW DL3 Photometry
13.11 Spectroscopic tables xp_summary Auxiliary information about the mean BP/RP spectrum of a given source Main NEW DL3 Photometry
13.10 Spectroscopic tables xp_epoch_crowding Information on both treated and untreated crowding for both BP and RP CCDs for a FoV transit Epoch NEW DL2 Photometry
08.05 Epoch-level astrometric, photometric and image products onboard_detection_af_xp Object logs from the astrometric field and the BP and RP fields Epoch NEW DL1 Photometry
13.07 Spectroscopic tables synthetic_photometry_gspc Synthetic photometry generated from the Gaia BP/RP mean spectra. Main   DL4 Photometry
01.05 Main source catalogues all_source_rvs Parameters such as radial velocities, spectral line broadening, and Grvs magnitudes, derived from the Radial Velocity Spectrometer (RVS). Main NEW DL3 Spectroscopy
08.06 Epoch-level astrometric, photometric and image products onboard_detection_rvs Object logs from radial velocity spectrometer (RVS) field Epoch NEW DL1 Spectroscopy
14.01 Variability tables vari_summary Information on where a source can be found in the different Variability tables and statistical parameters of timeseries Main   DL3 Variability
14.10 Variability tables vari_rad_vel_statistics Statistical parameters of radial velocity time series. Main NEW DL3 Variability
14.03 Variability tables vari_classifier_class_definition Detailed descriptions of all variability classifiers. Main     Variability
14.02 Variability tables vari_classifier_result Variability classification results of all classifiers. Main   DL4 Classification
14.0N Variability tables vari_unsupervised Unsupervised machine-learning classification for variable sources Main NEW DL4 Classification
14.06 Variability tables vari_cepheid Variable sources – Cepheids Main   DL4 Variability
14.07 Variability tables vari_compact_companion Variable sources – Compact companion candidates Main   DL4 Variability
14.08 Variability tables vari_eclipsing_binary Variable sources – Eclipsing binaries Main   DL4 Variability
14.12 Variability tables vari_long_period_variable Variable sources – Long-period variables Main   DL4 Variability
14.13 Variability tables vari_microlensing Variable sources – Microlensing events Main   DL4 Variability
14.15 Variability tables vari_planetary_transit Variable sources – Planetary transits Main   DL4 Variability
14.17 Variability tables vari_rrlyrae Variable sources – RR Lyrae stars Main   DL4 Variability
14.18 Variability tables vari_short_timescale Variable sources – Short-timescale variables Main   DL4 Variability
14.16 Variability tables vari_rotation_modulation Variable sources – Solar-like rotational modulation variables Main   DL4 Variability
14.05 Variability tables vari_agn Variable sources – Active galactic nuclei Main   DL4 Variability
14.11 Variability tables vari_flaring_star Variable sources - Flaring star Main NEW DL4 Variability
14.14 Variability tables vari_pms_oscillator Variable sources - Pre-main-sequence oscillators Main NEW DL4 Variability
14.19 Variability tables vari_yso Variable sources - Young stellar objects variability Main NEW DL4 Variability
10.01 Science alert tables science_alerts Gaia Photometric Science Alerts triggered in the time span covered by DR4, i.e. 25-07-2014 to 20-01-2020. Main   DL3 Classification
01.06 Main source catalogues all_source_flags Compiles a selection of flags for each source published in the Gaia catalogue. Main NEW DL3 Classification
10.02 Science alert tables alerts_mixedin_sourceids List of identifiers for mixed-in sources for Gaia Photometric Science Alerts, where transits from the primary source are mixed with other sources in the catalogue Main   DL3 Classification
02.02 Astrophysical parameter tables ap_class Classification probabilities and astrophysical parameters of sources derived by Discrete Source Classification (DSC), Outlier Analysis (OA), and UCA from the Apsis processing chain. Main   DL4 Classification
02.03 Astrophysical parameter tables ap_class_ir Classification probabilities and parameters of sources derived by DSC from the Apsis processing chain using Gaia data and external infrared photometry. Main NEW DL4 Classification
02.19 Astrophysical parameter tables mcmc_samples_gsp_phot Parameter distributions from MCMC chain of GSP-Phot Main   DL4 Parameters
02.04 Astrophysical parameter tables ap_emission Astrophysical properties of emission-line or active stars Main   DL4 Parameters
02.08 Astrophysical parameter tables ap_xp Astrophysical parameters from BP/RP spectra derived with APSIS Main   DL4 Parameters
02.10 Astrophysical parameter tables ap_xp_supp Astrophysical parameters from BP/RP spectra derived with GSP-Phot Main NEW DL4 Parameters
02.05 Astrophysical parameter tables ap_hot Astrophysical parameters of hot stars Main   DL4 Parameters
02.06 Astrophysical parameter tables ap_rvs Astrophysical parameters of stars derived from RVS spectra Main   DL4 Parameters
02.01 Astrophysical parameter tables ap_chem Abundances of chemical elements of stars derived from RVS spectra by GSP-Spec Main   DL4 Parameters
02.13 Astrophysical parameter tables total_galactic_extinction_map Total Galactic Extinction (TGE) map for the monochromatic extinction at 541.4 nm. Main   DL4 Parameters
02.14 Astrophysical parameter tables total_galactic_extinction_map_opt This table provides an optimum version of the Total Galactic Extinction\nmap at a single HEALPix level 9. Main   DL4 Parameters
02.12 Astrophysical parameter tables interstellar_medium_spectra Stacked Interstellar Medium Spectra as derived by DIB-Spec. Main   DL4 Spectra
02.11 Astrophysical parameter tables interstellar_medium_params Diffuse Interstellar Band (DIB) parameters derived from stacked spectra binned in galactic latitude, longitude and distance. Main   DL4 Parameters
TBD Cross-matches all_source_match Global cross-match table compiling all source_id associations between those in all_source_astrometry, gaia_source_environment, and crowded_field_source. Main NEW DL3 CrossMatch
13.08 Spectroscopic tables xp_continuous_mean_spectrum Mean BP and RP spectra based on the continuous representation in basis functions. Main   DL3 Spectra
13.09 Spectroscopic tables xp_epoch_spectrum Epoch BP and RP spectra collected at transit level for non-SSO sources. Epoch NEW DL2 Spectra
13.01 Spectroscopic tables rvs_mean_spectrum RVS mean sampled spectra. The spectra are in the rest frame and are normalised. Main   DL2 Spectra
13.04 Spectroscopic tables rvs_epoch_spectrum RVS spectra combined at the FOV-transit level. The spectra are in the solar barycentric frame and normalized Epoch NEW DL3 Spectra
13.05 Spectroscopic tables rvs_transit_description CCD level information for RVS transits Epoch NEW DL2 Spectra
06.08 Extra-galactic tables grav_lens_xp_mean_spectrum Mean BP/RP spectra of gravitational lens components Gravitational lensing NEW DL3 Spectra
02.17 Astrophysical parameter tables uca_neuron_information Each entry corresponds to parameters estimated for one particular neuron of the Self-Organised Map using the UCA module Main NEW DL4 Parameters
02.15 Astrophysical parameter tables oa_neuron_information Each entry corresponds to parameters estimated for one particular neuron of the Self-Organised Map using the Outlier Analysis (OA) module. Main   DL4 Parameters
02.16 Astrophysical parameter tables oa_neuron_xp_spectra Prototype BP/RP spectrum corresponding to each of the neurons of the Self-Organised Map produced by the Outlier Analysis Main   DL3 Spectra
02.18 Astrophysical parameter tables uca_neuron_xp_spectra Prototype BP/RP spectrum for a particular neuron given in the uca_neuron_information table. Main NEW DL3 Spectra
03.04 Crowded fields crowded_field_image Images of crowded-fields published as FITS files. Image NEW DL1 Image
03.02 Crowded fields crowded_field_coverage_map Coverage maps of Crowded Fields. For each HEALPix cell covering the crowded field region the number of scans is given. Auxiliary NEW DL1 Image
07.01 Non-single stars tables nss_acceleration_astro Non-single-star astrometric solution parameters for sources having a non-linear proper motion which is compatible with an acceleration solution. Non-single star   DL3 Astrometry
07.03 Non-single stars tables nss_non_linear_spectro Non-single stars - accelerated spectroscopic solutions Non-single star   DL3 Spectroscopy
07.04 Non-single stars tables nss_two_body_orbit Non-single-star orbital solution parameters for sources compatible with an orbital two-body solution. This covers astrometric binaries, spectroscopic binaries, eclipsing binaries and certain combinations thereof. Non-single star   DL3 Astrometry
13.06 Spectroscopic tables rvs_two_body_orbit Non-single stars - spectroscopic binary solutions obtained using both the astrometric orbital solutions and the cross-correlation functions between RVS epoch spectra and synthetic spectral templates. Non-single star NEW DL3 Spectroscopy
07.0N Non-single stars tables nss_masses Non-single stars - masses of companions Non-single star   DL3 Parameters
07.02 Non-single stars tables nss_multiplicity Source may be involved in more than one resolved pair. This table list all pairs involving a given source. Non-single star NEW DL3 Astrometry
07.05 Non-single stars tables nss_vim_fl Non-single-star solution parameters for sources compatible with a Variability-Induced Mover (VIM) solution. Non-single star   DL3 Astrometry
08.01 Epoch-level astrometric, photometric and image products epoch_astrometry Time series of astrometric data, i.e. individual astrometric measurements for all sources treated in the main astrometric processing. Epoch NEW DL2 Astrometry
08.04 Epoch-level astrometric, photometric and image products epoch_image Image data from the Gaia CCDs for all sources treated in the main astrometric processing. These are pre-processed and sky-projected individual CCD sample values. Epoch NEW DL1 Image
03.03 Crowded fields crowded_field_epoch_astrometry Time series of astrometric data, i.e. the individual astrometric measurements for the sources treated in the special crowded-field processing. Epoch NEW DL2 Astrometry
08.07 Epoch-level astrometric, photometric and image products bright_source_epoch_astrometry Time series of astrometric data, i.e. the individual astrometric measurements for the same 48 among the 51 brightest stars for which the astrometric parameters are presented in the bright_source_astrometry table. Epoch NEW DL2 Astrometry
08.02 Epoch-level astrometric, photometric and image products epoch_photometry Time series of photometric data aggregated per FOV-transit, i.e. the light curve at FoV level for a given source in the G, BP and RP bands. Epoch NEW DL2 Photometry
08.03 Epoch-level astrometric, photometric and image products epoch_photometry_ccd Time series of photometric data at CCD-transit level, i.e. the light curve at FoV level for a given source in the G band. Epoch NEW DL2 Photometry
03.0N Crowded fields crowded_field_epoch_photometry Time series of photometric data, i.e. the individual photometric measurements for the sources treated in the special crowded-field processing. Epoch NEW DL2 Photometry
13.03 Spectroscopic tables rvs_epoch_data_double FOV-transit-level information for the radial velocity, spectral line broadening, and Grvs magnitudes for double-lined transits. Epoch NEW DL2 Spectroscopy
13.02 Spectroscopic tables rvs_epoch_data_single FOV-transit-level information for radial velocity, spectral line broadening, and Grvs magnitudes for single-lined transits. Epoch NEW DL2 Spectroscopy
02.09 Astrophysical parameter tables ap_xp_epoch Astrophysical parameters derived from the epoch RP spectra for ultra-cool dwarfs. Epoch NEW DL4 Parameters
02.07 Astrophysical parameter tables ap_rvs_epoch Astrophysical parameters, and in some cases the abundances, derived from the epoch Radial Velocity Spectrometer (RVS) spectra for RRLyrae and Cepheids by GSP-Spec. Epoch NEW DL4 Parameters
06.09 Extra-galactic tables qso_candidates Parameters derived from various modules dedicated to the classification and characterisation of sources considered as QSO candidates. Quasar   DL3 Parameters
06.10 Extra-galactic tables qso_catalogue_name List of input catalogues used to select those sources for which morphological analysis was performed in the QSO candidates table. Quasar   DL3 Classification
06.04 Extra-galactic tables grav_lens_combination Information relevant at the level of a gravitational lens multiplet system analysed around lensed sources. Gravitational lensing   DL3 Parameters
06.03 Extra-galactic tables grav_lens_catalogue_name List of input catalogues used to select any given source analysed by the Gravitational Lens module. Gravitational lensing   DL3 Classification
06.05 Extra-galactic tables grav_lens_component Potential gravitational lens components (including the quasars). Gravitational lensing   DL3 Classification
06.06 Extra-galactic tables grav_lens_observation Observations used for gravitational lens search. Gravitational lensing   DL2 Classification
06.07 Extra-galactic tables grav_lens_outlier Individual observations that have been discarded as outliers from the analysis of the gravitational lenses. Gravitational lensing   DL3 Classification
06.01 Extra-galactic tables galaxy_candidates Parameters derived from various modules dedicated to the classification and characterisation of sources considered as galaxy candidates. Galaxies   DL3 Parameters
06.02 Extra-galactic tables galaxy_catalogue_name List of input catalogues used to select any given source for which morphological analysis parameters are provided in the Galaxy candidates table. Galaxies   DL3 Classification
12.02 Solar System object tables sso_source Solar system objects - Data related to Solar System objects observed by Gaia. Solar System   DL3 Parameters
12.06 Solar System object tables sso_observation_unknown Solar system objects - Each table line contains observation data obtained during the transit of the source on a single CCD, during a single transit. The source is considered to be of unknown type. Solar System NEW DL3 Classification
12.01 Solar System object tables sso_alerts Solar system objects - Observations that have have been associated with published asteroid alerts. Solar System NEW DL3 Classification
12.03 Solar System object tables sso_observation_asteroid Solar system objects - Each table line contains observation data obtained during the transit of the source on a single CCD, during a single transit. The source is considered to be of type asteroid. Solar System NEW DL2 Astrometry
12.07 Solar System object tables sso_reflectance_spectrum Solar system objects - Mean BP/RP reflectance spectra of asteroids computed as the ratio between the asteroid flux and an averaged solar analogue flux. Solar System   DL3 Spectra
12.05 Solar System object tables sso_observation_satellite Solar system objects - Each table line contains observation data obtained during the transit of the source on a single CCD, during a single transit. The source is considered to be of type planetary satellite. Solar System NEW DL2 Astrometry
12.04 Solar System object tables sso_observation_comet Solar system objects - Each table line contains observation data obtained during the transit of the source on a single CCD, during a single transit. The source is considered to be of type comet. Solar System NEW DL2 Astrometry
11.01 Simulation tables gaia_source_simulation Gaia Simulations (GOG). Table of sources realised according to the Gaia Object Generator (GOG) simulation. Simulations     Simulations
11.02 Simulation tables gum_mw Gaia Simulations (GUM Milky Way). Table of simulated galactic stars according to the Gaia Universal Model Simulation (GUMS). Simulations     Simulations
11.03 Simulation tables gum_galaxy Gaia Simulations (GUM Galaxies). Simulations NEW   Simulations
11.04 Simulation tables gum_qso Gaia Simulations (GUM QSO). Simulations NEW   Simulations
11.05 Simulation tables gum_sn Gaia Simulations (GUM Supernovae). Simulations NEW   Simulations
04.01 Auxiliary tables commanded_scan_law Representation of the Gaia scanning law over the 66 month time period covered by the Gaia Data Release 4 including the Ecliptic Pole Scanning at the beginning of the mission. Auxiliary     General
04.02 Auxiliary tables bam_observation Data from the Basic-Angle Monitor (BAM), i.e. from the on-board metrology interferometer designed to continually measure the variations of the effective angle between the viewing directions of the two Gaia fields of view. Auxiliary NEW DL1 Image
04.03 Auxiliary tables gaia_gap This table lists all time intervals excluded from the astrometric, photometric and/or spectroscopic data processing of the Gaia observations. Gaps are time periods where such observations have been ignored in the various processing pipelines. Auxiliary NEW in Archive   General
04.04 Auxiliary tables gbot_observation Ground-based position measurements of the Gaia satellite taken by the GBOT project for the purpose of Gaia orbit reconstruction. Auxiliary NEW   General

 

Background of the data

Gaia DR4 data is based on data collected between 25 July 2014 (10:30 UTC) and 20 January 2020 (22:00 UTC) spanning a period of 66 months of data collection. As a comparison, Gaia DR3 was based on 34 months of data, Gaia DR2 was based on 22 months of data, and Gaia DR1 was based on observations collected in the first 14 months of Gaia's routine operational phase.

The reference epoch for Gaia DR4 is J2017.5. Remember that the reference epoch is different for each Gaia data release, and that the reference epoch for Gaia DR3 was J2016.0, for Gaia DR2 was J2015.5, and for Gaia DR1 was J2015.0.

Positions and proper motions are referred to the ICRS, to which the optical reference frame defined by Gaia DR4 (Gaia-CRF4) is aligned. The time coordinate for Gaia DR4 results is the barycentric coordinate time (TCB).

 

Gaia Source Identifiers

Sources in the Gaia Catalogue are all identified through the Gaia Source Identifier, i.e., the source_id field in the various tables in the Gaia Archive. The construction of the source identifiers is explained in the archive documentation (for Gaia DR1, see the data model section). In particular, the source_id number contains rough information about the source position on the sky.

As explained in previous announcements, there are various reasons why the identifier of a specific source may change or disappear when going from the Gaia DR1 to the Gaia DR2 source list and on to the Gaia DR3 and Gaia DR4 source lists. Users of Gaia data should thus be aware that the source list for Gaia DR4 should be treated as independent from Gaia DR3, Gaia DR2, and from Gaia DR1. With each new Gaia data release, the source list is becoming progressively more stable.

The Gaia source names ('designations') for Gaia DR4 are all constructed as follows:

Gaia DR4 yyy....yy

 

Accessing the data

The Gaia ESA Archive will be the main point of access to the Gaia DR4 data, but the data (or a subset thereof) will also be served from our partner data centres (CDS, ASDC, ARI, AIP and Flatiron). Data can be extracted from the Gaia Archive by performing ADQL queries and downloading the corresponding results tables.

The total size will be about 500 TB, of which a large fraction is the level-2 (epoch) data.

 

Passbands

Gaia DR4 photometric passbands will be published to document how the Gaia DR4 magnitudes are computed, and to allow reproducing the analysis of the data.

 

Documentation

Data release documentation is provided along with each data release in the form of a downloadable PDF and a webpage, plus a set of Data Release papers describing the processing and performance of the catalogue. Please visit the Gaia ESA Archive support pages to access Gaia documentation, and make sure to go through all relevant information given from the documentation overview page.

 

Known issues with Gaia Data Release 4

A list of issues with the data or info given along with the data will be provided. In case you find an issue with the data yourself, please contact the Gaia Helpdesk to let us know.

 

Data model

The Gaia DR4 data model describes all tables together with the names and contents of the columns inside each table. This information will become available from the Gaia ESA Archive along with the data release documentation.

 

In advance of Gaia DR4, we will publish a draft version of the data model here.

 

Data Release papers

Along with the Gaia DR4 data release documentation, several data processing papers will be published describing the specifics of the data processing and validation performed by the different coordination units in the Gaia Data Processing and Analysis Consortium (DPAC). There will also be some papers on the performance verification of Gaia, providing basic demonstrations of the scientific potential of the Gaia DR4 catalogue. Some pre-release processing papers are already available.