13.2.3 Data Link

As defined in the Gaia Data Releases Scenario, different Gaia data releases will provide additional information for the catalogue sources. Apart from the five-parameter solution, other data sets like lightcurves, spectroscopic data, variable stars classifications, etc will be added in connection with the main Gaia catalogue. This imposes a technical challenge to guarantee that the approach followed for the different versions of the Gaia Archive for the publication of the Gaia data can be maintained and extended in future data releases without major impact on the performance or in the methods to be used to consume it by the scientific community.

To do that, the Gaia Archive prepared for DR2 offers the first implementation of a quite flexible IVOA protocol called DataLink. This protocol allows the discovery of extra metadata associated to a certain row (source) by the publication of a RESTful protocol that includes links to different kinds of data, including Time Series, Spectral data or calibration files.

For this version, the general Data Link service and the access to photometric time series (for the limited number variables providing light curves) is already offered. This service could be extended in sucessive data releases following the same approach so the users will be able to easily adapt their scripts to discover new data resources.

The Archive online help http://gea.esac.esa.int/archive-help provides both a detailed description of the interfaces (Datalink service section) and a hands-on tutorial on how to work with DR2 light curves (Tutorials - Datalink and light curves section).