Artistic print of ESA’s Gaia satellite observing the Milky Way. The background image of the sky has been compiled from data from more than 1.8 billion stars. Shows the total brightness and color of the stars observed by Gaia published as part of Gaia’s Early Data Release 3 (Gaia EDR3) in December 2020. Credit: Spaceship: ESA / ATG medialab; Milky Way: ESA / Gaia / DPAC; CC BY-SA 3.0 UP. Acknowledgment: A. Moitinho.
Gaia is ESA’s mission to create the most accurate and complete multidimensional map of the Milky Way. This allows astronomers to reconstruct the structure of our galaxy and its evolution over billions of years, and to better understand the life cycle of stars and our place in the universe.
Gaia Data Release 3 contains new and improved details of nearly two billion stars in our galaxy. The catalog includes new information that includes chemical compositions, stellar temperatures, colors, masses, ages, and the speed with which stars move toward or away from us (radial velocity). Much of this information was revealed by recently published spectroscopy data, a technique in which starlight is divided into its constituent colors (such as a rainbow). The data also includes special subsets of stars, such as those that change brightness over time.
Also in this dataset is the largest catalog of binary stars, thousands of objects in the solar system such as asteroids and planets, and millions of galaxies and quasars outside the Milky Way.
Starquakes
One of the most surprising findings from the new data is that Gaia is able to detect earthquakes (small movements on the surface of a star) that change the shape of stars, for which the observatory was not built. originally.
Previously, Gaia found radial oscillations that cause stars to swell and shrink periodically, maintaining their spherical shape. But Gaia has now also detected other vibrations that are more like large-scale tsunamis. These non-radial oscillations change the overall shape of a star and are therefore more difficult to detect.
Gaia found strong non-radial earthquakes in thousands of stars. Gaia also revealed these vibrations to stars that had rarely been seen before. These stars should not have any earthquakes according to current theory, while Gaia did detect them on its surface.
“The Starquakes teach us a lot about stars, especially their inner workings. Gaia is opening a gold mine for the ‘asterosismology’ of massive stars,” says Conny Aerts of KU Leuven in Belgium, a member of the Gaia collaboration.
The DNA of the stars
What the stars are made of can tell us their place of birth and their subsequent journey, and therefore the history of the Milky Way. With today’s release of data, Gaia is revealing the largest chemical map of the galaxy coupled with 3D motion, from our solar district to the smaller galaxies around us.
Some stars contain more “heavy metals” than others. Only light elements (hydrogen and helium) formed during the Big Bang. All other heavier elements, called metals by astronomers, are built inside the stars. When stars die, they release these metals into the gas and dust between the stars, called the interstellar medium, from which new stars form. The formation of active stars and death will lead to a richer metal environment. Therefore, the chemical composition of a star is somewhat similar to its DNA, which provides us with crucial information about its origin.
With Gaia, we see that some stars in our galaxy are made of primordial material, while others like our sun are made of matter enriched by previous generations of stars. Stars that are closer to the center and plane of our galaxy are richer in metals than stars at greater distances. Gaia also identified stars that originally came from galaxies other than our own, based on their chemical composition.
“Our galaxy is a beautiful crucible of stars,” says Alejandra Recio-Blanco of the Côte d’Azur Observatory in France, who is a member of the Gaia collaboration.
“This diversity is extremely important because it tells us the history of the formation of our galaxy. It reveals the processes of migration within our galaxy and the growth of outer galaxies. It also clearly shows that our sun, and we, we all belong to a constantly changing world, a system formed by the coupling of stars and gases from different sources. “
Binary stars, asteroids, quasars and more
Other articles published today reflect the breadth and depth of Gaia’s discovery potential. A new catalog of binary stars presents the mass and evolution of more than 800,000 binary systems, while a new study of asteroids that includes 156,000 rocky bodies is delving into the origin of our solar system. Gaia is also revealing information about 10 million variable stars, mysterious macromolecules between stars, as well as quasars and galaxies beyond our own cosmic neighborhood.
“Unlike other missions that target specific objects, Gaia is a survey mission. This means that while examining the entire sky with billions of stars several times, Gaia is forced to make discoveries that others “This is one of its strengths, and we can’t wait for the astronomy community to dive into our new data to find out even more about our galaxy and its environment than we could imagine.” says Timo Prusti, a Gaia project scientist at ESA.
Gaia is ESA’s mission to create the most accurate and complete multidimensional map of the Milky Way. This allows astronomers to reconstruct the structure of our galaxy and its evolution over billions of years, and to better understand the life cycle of stars and our place in the universe.
Video: Gaia, the billion-star surveyor More information: Gaia in depth: www.cosmos.esa.int/web/gaia/data-release-3
Gaia images: www.esa.int/ESA_Multimedia/Sea… a & result_type = images
Provided by the European Space Agency
Citation: Gaia sees strange stars in the most detailed Milky Way survey to date (2022, June 13) retrieved June 13, 2022 from
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