CDS maintains a database of all known astronomical objects (stars, quasars, galaxies, etc.). At end 2016, 8.5 million objects were recorded in this database to which half a million objects are added every year from scientific papers, data catalogues, images and other published sources. CDS thus provides instant access to all existing data on astronomical objects, as well as search, correlation, data mining and image processing tools.

CDS is consulted more than 500,000 times a day, in France by some 3,000 research scientists and by astronomers all over the world, who sometimes use it without even knowing, since CDS partners a number of mirror sites that provide a gateway to its database.

CDS is hosted by the Strasbourg Astronomical Observatory (ObAS), a joint research unit of the French national scientific research centre CNRS and the University of Strasbourg. It is a national research infrastructure recognized by CNRS offering unique access to data from a range of partner agencies and observatories such as ESA, ESO, NASA, NAOC (China), NAOJ (Japan) and INASAN (Russia).

The virtual observatory is funded by CNES for space data exploitation, and by European funding. CDS represents France on the International Virtual Observatory Alliance (IVOA), which defines formats and rules for astronomers publishing data sets so that they can be readily used by data centres like CDS.

See the CDS website