Carl Sagan said that we are stardust and, in turn, we are the formula for the cosmos to know itself. Serve this preamble phrase for the most stellar news of the day. This Monday, the European Space Agency (ESA) publishes the third installment of data from the Gaia mission: the space probe in charge of portraying our own galaxy. After almost a decade of work, this spectacular space camera has managed to create the more accurate and complete map up to the date of Milky Waywith information about 2 billion stars of our galactic neighborhood.
The new atlas of the Milky Way, forged by an international network of researchers with extensive Spanish participation, debut in style. On the one hand, it collects the brightness of hitherto unknown stars, as well as the trail of thousands of celestial objects, asteroids, moons, galaxies and quasars from inside and outside the Solar System. On the other hand, Gaia also achieves a complete X-ray of the chemical composition, temperature, colors, masses, ages and speed to which the stars approach or move away from us.
According to the scientific team in charge of this celestial cartography, Gaia’s work has made it possible to reconstruct the structure of the Milky Way for billions of years, in addition to better understanding the life cycle of stars and our place in the universe. “We have never had so much information about our galaxy like now,” says carme jordi, researcher at the Institut de Ciències del Cosmos (ICCUB-IEEC) and one of the main scientists of the Gaia project. “A veritable treasure trove of data and who knows what discoveries will come out of here“, Add.
The third installment of Gaia data shows, for the first time in history, a panorama of the movement of 33 million stars of our galaxythe most complete catalog to date binary stars of the Milky Way and the first study of low resolution spectroscopy of thousands of celestial bodies (that is, the analysis of the physical properties of these objects). “We are used to news that talk about the history of a particular star, but now, thanks to Gaia, we have complete data on almost 200 million stars,” he illustrates. Joseph Manel Carrascoscientist at the Institut de Ciències del Cosmos (ICCUB-IEEC) and member of the Gaia scientific team.
Galactic Chemistry and Starquakes
After almost a decade observing the stars and collecting data on their wanderings, Gaia has managed to trace a chemical overview of the Milky Way. This analysis shows that while some stars in our galaxy are composed of primordial materialothers, like our Sun, contain traces of previous generations of stars. “Our galaxy is a beautiful crucible of stars“, explains Alejandra Recio-Blanco, a researcher at the Observatoire de la Côte d’Azur in France and one of the scientists who has contributed to building this latest galactic map. “This diversity is extremely important, as it tells us the story of the formation of our galaxy. It also shows that our sun and all of us belong to a constantly changing system, formed thanks to the union of stars and gas from different origins“says the scientist.
“Our galaxy is a beautiful melting pot of stars”
Gaia has also managed to glimpse one of the fascinating phenomena of the cosmos; the starquakessome small ‘tsunamis’ recorded on the surface of stars and that alter their shape. the european satellite was not designed to detect this type of process and, in fact, it was not even foreseen that at some point he would be able to observe them. But thanks to the work of scientists on Earth, Gaia has managed to record stellar earthquakes in thousands of stars of our galactic neighborhood. “Gaia opens a gold mine for asteroseismology“, explains Conny Aerts from Ku Leuven, a member of the research team.
Another of the great novelties presented today by Gaia is the most complete study to date of the 156,000 asteroids that swarm in our Solar System: from those closest to Earth, the asteroid belt between Mars and Jupiter to the Trojans, Centaurs and transneptunian objects. Beyond the confines of the Milky Way, Gaia has also glimpsed nearly two million quasars (a type of supermassive black holes) and about three million galaxies.
The European mission Gaia began to conceive early nineties. In 2013, the satellite took off from its mother planet and began its journey through the cosmos until it reached a strategic point located 1.5 million kilometers from the earth. From there, equipped with a 1 billion pixel camera and an arsenal of scientific instruments, the satellite has spent nearly a decade in orbit (although the vast majority of scientific observations themselves occurred between 2017 and 2018). Since then, Gaia has already added more than 2,850 days of sky observation and can boast of having collected 100 terabytes of data of our galaxy.