STORY – The European space telescope has made it possible to determine the position, distance, speed and also the color of millions of stars.
How to account for the importance of the Gaia space mission, without falling into the pitfall of listing strictly astronomical figures? The challenge is complicated, not to say impossible. This satellite of the European Space Agency (ESA) has been working since 2013 to carry out the most exhaustive astrometric survey ever carried out. On Monday, almost ten years after the mission took off, its scientists unveiled the first “complete” version of this catalog.
“Gaia has carried out a systematic survey of all objects up to 500,000 times fainter than what can be distinguished with the naked eye”, sums up François Mignard, research director emeritus at the Observatoire de la Côte d’Azur, and one of the great craftsmen of Gaia. It can be both extremely bright but very distant objects (several billion light-years) such as active galactic nuclei (supermassive black holes that emit intense radiation by swallowing large amounts of…