In section 14. Catalogs and data
Gaia Universe model snapshot
This paper describes an accurate simulation of the sky as it will be seen by the Gaia spacecraft, and as such it is a valuable resource that summarizes the outcome of many years of effort by the ESA Gaia community. It estimates the number of objects that can be potentially detected, along with their theoretical photometric, astrometric, and spectroscopic characteristics. It is predicted that Gaia will be able to observe 1.1 billion stars, either singles or part of multiple star systems, of which about 3% will have one or more exoplanets. In addition, several million galaxies could be detected: half a million to 1 million of quasars and up to 50,000 supernovae will be potentially discovered during the 5 years of the Gaia mission.