Carte du Ciel (ESA CduC)
In the project, photographic plates obtained during the Carte du Ciel -project will be digitised and the positions of the stars will be remeasured. Carte du Ciel was an international project, initiated in the late 19th century, to obtain accurate positions for millions of stars. The mapping of the night sky was accomplished by taking exposures on photographic glass plates. Helsinki University Observatory was one of the participating observatories. As a whole, the project turned out to be too laborious, and only some of the results have ever been published.
Gaia is a satellite by ESA (European Space Agency), with a mission to determine accurate positions and distances for about one billion stars in our Galaxy. The first star catalog by Gaia is to be released in the summer 2016. By combining the data from the Carte du Ciel and Gaia we can study the proper motions and brightnesses of stars over a timespan of about 100 years.