Gaia sizes up 1.1 billion stars

Gaia, a European Space Agency satellite designed to unlock the secrets of the birth and evolution of the Milky Way, has released its first wave of data on the positions and brightness for about one billion stars. Its mission is to produce the most detailed map ever made of the Galaxy and final results are expected in the early 2020s. 'The Milky Way and its immediate neighbours are the only galaxies that can be studied in detail, star-by-star, making this a really exciting mission. Although not the complete picture, this first data release is a significant milestone and will be one of several over the next six years,' explained Professor Mark Cropper, Gaia team lead at UCL Mullard Space Science Laboratory (UCL MSSL) UCL MSSL has contributed significantly to Gaia for 15 years by testing and calibrating each of the 106 electronic detectors used to capture the data shared today. It's also taken a critical role in the development of Gaia's state-of-the-art Radial Velocity Spectrometer (RVS) and processing the data from it. The RVS provides the speed and temperature of each star as well as its size and age; results from it are expected to be announced in approximately a year's time. Gaia has a suite of tools including two telescopes which each focus on the same large array of  electronic detectors to calculate the position of each star with unprecedented accuracy.