By François Mignard, research director emeritus CNRS, member of the Bureau des longitudes
On April 25, 2018, ESA and the European consortium DPAC delivered the second version of the results produced by Gaia satellite observations. By the diversity of data, their volume and especially the extreme precision of astrometry and photometry, it is an important date in the history of astronomy that has been written. The history of the Milky Way is at the center of this space mission and I will explain why astronomers have been working so hard for over two centuries to track stellar distances and the reasons that have led Europe to want to do so. for a billion stars in our galaxy.
Admission free within the limits of available places.
