ESA unveils its third catalog of Milky Way data
Eva Deschamps / June 14, 2022
The Gaia mission unveiled on Monday its third catalog of data on the Milky Way, the galaxy where the Earth is located, announced the European Space Agency (ESA), at the initiative of this mission.
This new data set includes more precise details on nearly two billion stars in the galaxy. Chemical compositions, stellar temperatures, colors, masses, ages, and the speed at which the stars are approaching or receding from Earth are all new information obtained through spectroscopy, a technique that uses the light spectrum of stellar light.
The data also revealed Gaia's ability to detect stellar wobbles, tiny motions on the surface of a star that change its shape, something the satellite was not originally designed to do. Stellar quakes tell us a lot about stars, including their inner workings. Gaia opens a gold mine for the 'asteroseismology' of massive stars, explains Conny Aerts, from the KU Leuven, member of the Gaia collaboration.
The satellite has also learned more about the chemical composition of stars, which provides information on their birthplace and their subsequent journey, and thus on the history of the Milky Way. The catalog published Monday thus offers the largest chemical map of the galaxy. The chemical composition of a star is a bit like its DNA, giving us crucial information about its origin, says ESA. With Gaia, we see that some stars in our galaxy are made of primordial matter, while others like our Sun are made of matter enriched by previous generations of stars. Stars closer to the center and plane of our galaxy are more metal-rich than stars at greater distances.
This new set also contains the largest catalog to date of binary stars, thousands of solar system objects such as asteroids and satellites of planets. It presents the orbital characteristics of more than 800,000 binary systems, as well as a new study of asteroids including 156,000 rocky bodies. Gaia also reveals information about 10 million variable stars, mysterious macromolecules between stars, and quasars and galaxies beyond our own cosmic neighborhood.
Launched in December 2013 by ESA, the Gaia satellite aims to map a part of our galaxy. In particular by listing nearly a billion celestial objects (stars, exoplanets ...), estimating the distance that separates them from the earth as well as their proper speed. Thanks to these observations, astronomers hope to lift the veil on the formation, structure and history of the Milky Way.