When calculating the distances to stars, researchers typically measure stellar parallax — the perceived movement of a star based on Earth’s changing position in its orbit around the Sun. However, thanks to Gaia’s meticulous measurements, the researchers will be able to differentiate between a star’s parallax its actual stellar movement. Both the parallax and actual movements of 1.3 billion stars will be featured in the catalogue, with direct distances estimated for about 10 percent of those stars.

Gaia also recorded the brightness of each star and measured the color of almost all of the 1.7 billion stars surveyed. From this, the researchers created an extremely detailed Hertzsprung-Russell diagram — a chart that compares the brightness of stars to their colors. The diagram, which is made up of four million stars that lie within 5,000 light-years of the Sun, will allow astronomers to study the population and evolution of stars in various parts of the Milky Way.