The European Space Agency’s Gaia mission, which is working to create the most complete multidimensional map of our galaxy, today revealed new information about nearly two billion stars found in the Milky Way and the largest known “chemical map”. yet.
Gaia’s new publication includes details on temperatures, colors, ages, radial velocities and chemical compositions of stars, among other characteristics, based on data collected between 2014 and 2017. It also provides information on exoplanets, binary stars and the interstellar medium, or that is, what is among the stars.
The study used a technique called spectroscopy, which involves splitting starlight into its component colors. This is the largest low-resolution spectroscopy study ever done.
The composition of stars can tell us about their birthplace and subsequent trajectory, and therefore about the history of the Milky Way.
Composition of the Milky Way stars
The European agency, known by the acronym ESA, explains that during the Big Bang only light elements such as hydrogen and helium were formed and that the heaviest, which astronomers call metals, are created inside the stars.
Some stars have more “heavy metals” than others, the agency says, explaining that when they die, they release them “into the gas and dust we find between stars, called the interstellar medium, from which new stars form.”
Of the Milky Way’s stars, some are made of “primordial material” and others have enriched matter from earlier stars, such as the Sun. “Stars closer to the center and plane of our galaxy are richer in metals compared to stars located at a greater distance,” explains ESA.
Star diversity is “extremely important as it tells us the story of the formation of our galaxy. It reveals the migration processes within our galaxy and the accretion of outer galaxies. It also clearly shows that our Sun and we all belong to a system in continuous change, formed thanks to the encounter of stars and gases of different origins”, explained Alejandra Recio-Blanco, member of the Gaia Collaboration at the Côte d’Azur Observatory in France.
“Stellar Earthquakes”
The Gaia mission has also detected small movements on the surface of stars that it calls “stellar earthquakes” or “Starquakes” that cause the shape of these celestial bodies to change.
Previously, radial oscillations were identified that caused periodic changes in the size of stars while maintaining the same shape. This is what differentiates them from those detected now.
“Starquakes” give us a lot of information about stars, especially about their inner workings,” said Conny Aerts from Ku Leuven in Belgium, a member of the Gaia Collaboration.
The new Gaia publication also brings information about 1.9 million quasars and 2.9 million galaxies outside the Milky Way.
Gaia is an open science mission, meaning its catalog is open to anyone who wants to access it, ESA explained in 2018, with the second publication of data. According to calculations, by the end of the mission in 2024 it could contain a peta byte of information.
All its data will be archived at ESA “so that it can be used by the scientific community to carry out research not only on the Milky Way, but also serve as a reference system for other types of observations or confirm astrophysical theories that until now only mathematical models existed. ,” the statement said.
Source: CNN Brasil
