European researchers have mapped 1.15 billion stars, the most precise and detailed sky survey to date. The task took a thousand days to accomplish using the Gaia spacecraft, which was launched on Dec. 19, 2013.

The map was made possible by 450 researchers from 25 European countries. One hundred scientists are French, including those from CNRS (Délégation Paris Michel-Ange), Observatoire de Paris, Observatoire de la Côte d’Azur and the French space agency CNES.

The Gaia spacecraft has two telescopes and 106 CCDs that form the equivalent of a camera with a resolution of a billion pixels.


It orbits around Earth while surveying the sky, recording about 50 million stars each day. The map consists of 200 million more stars than they planned.

The survey will help scientists estimate important statistics of different types of celestial bodies. As of now, the team’s catalog contains data of around 250,000 quasars, 3,000 Cepheid and RR Lyrae variable stars.

The Gaia spacecraft also helps scientists determine the light curves of stars, which means the changes in the stars’ brightness. These observations will help scientists gather more insights about the different physical processes that influence these stars.

The collection of the catalog data may have ended in September 2015 but the spacecraft still continues to gather more information. According to the research team, this would allow them to compare future positions of stars with the positions that are currently stated in the catalog. Moreover, they expect to complete their investigations about the velocity and distance of the billion stars by 2017.

In a press release, the researchers acknowledged the following laboratories that took part in the mission:

– Laboratoire Galaxies, Étoiles, Physique et Instrumentation (CNRS/Observatoire de Paris/Université Paris Diderot)

– Laboratoire Systèmes de Référence Temps-Espace (CNRS/Observatoire de Paris/UPMC)

– Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères (CNRS/Observatoire de Paris/ENS Paris/UPMC/Université de Cergy-Pontoise)

– Institut de Mécanique Céleste et de Calcul des Éphémérides (CNRS/Observatoire de Paris/UPMC/Université de Lille)

– Laboratoire Lagrange (CNRS/Observatoire de la Côte d’Azur/Université de Nice Sophia Antipolis)

– Laboratoire d’Astrophysique de Bordeaux (CNRS/Université de Bordeaux)

– Observatoire Astronomique de Strasbourg (CNRS/Université de Strasbourg)

– Laboratoire Univers, Transport, Interfaces, Nanostructures, Atmosphère et Environnement, Molécules (CNRS/Université de Franche-Comté)

– Laboratoire Univers et Particules de Montpellier (CNRS/Université Montpellier)