Aardbevingen! Gaia-ruimtevaartuig ziet vreemde sterren in meest gedetailleerde Melkwegonderzoek tot nu toe

Gaia is de missie van de European Space Agency (ESA) om een ​​nauwkeurige 3D-kaart te maken van meer dan een miljard sterren aan de overkant[{” attribute=””>Milky Way galaxy and beyond. Although it launched all the way back in 2013, it is still working to accurately map the the motions, luminosity, temperature and composition of the stars in our galaxy.

Along the way it has made numerous discoveries, such as detecting a shake in the Milky Way, the observation of almost 500 explosions in galaxy cores, crystallization in white dwarfs, and discovering a billion-year-old river of stars. It also revealed the total weight of the Milky Way, a direct measurement of the galactic bar in the Milky Way, mysterious fossil spiral arms in the Milky Way, and a new member of the Milky Way family.

Today marks the data of the third data release from Gaia. The first data release was on September 14, 2016, followed by the second data release on April 25, 2018. On December 3, 2020, they did an early third data release with detailed data on more than 1.8 billion stars. All this data is helping to reveal the origin, structure, and evolutionary history of our galaxy.

This image shows four sky maps made with the new ESA Gaia data released on June 13, 2022. Credit: © ESA/Gaia/DPAC; CC BY-SA 3.0 IGO

Today (June 13, 2022), ESA’s Gaia mission releases its new treasure trove of data about our home galaxy. Astronomers describe strange ‘starquakes’, stellar DNA, asymmetric motions, and other fascinating insights in this most detailed Milky Way survey to date.

Gaia is ESA’s mission to create the most accurate and complete multi-dimensional map of the Milky Way. This allows astronomers to reconstruct our home galaxy’s structure and past evolution over billions of years, and to better understand the lifecycle of stars and our place in the Universe.

Wat is er nieuw in gegevensversie 3?

De Gaia 3-gegevensrelease bevat nieuwe en verbeterde details van bijna twee miljard sterren in onze melkweg. De catalogus bevat nieuwe informatie, waaronder: chemische samenstellingenstellaire temperaturen, kleuren, massa’s, leeftijden en de snelheid waarmee sterren naar ons toe of van ons af bewegen (radiale snelheid). Veel van deze informatie werd onthuld door de onlangs vrijgegeven spectroscopie Data, een technologie waarbij sterrenlicht wordt opgedeeld in zijn samenstellende kleuren (zoals een regenboog). De gegevens bevatten ook speciale subsets van sterren, zoals sterren die in de loop van de tijd van helderheid veranderen.

Ook nieuw in deze dataset is de grootste catalogus tot nu toe van dubbelsterren, duizenden objecten in het zonnestelsel zoals asteroïden en planetaire manen, en miljoenen sterrenstelsels en quasars buiten de Melkweg.

aardbevingen

Een van de meest verrassende ontdekkingen die uit de nieuwe gegevens naar voren komen, is dat Gaia in staat is om stellaire aardbevingen te detecteren – kleine bewegingen op het oppervlak van een ster – die de vorm van sterren veranderen, iets waarvoor het observatorium oorspronkelijk niet was gebouwd.

Eerder had Gaia al radiale oscillaties gevonden die ervoor zorgen dat sterren periodiek opzwellen en samentrekken, terwijl ze hun bolvorm behouden. Maar Gaya heeft nu ook andere trillingen gedetecteerd die sterk lijken op een grootschalige tsunami. Deze niet-radiale oscillaties veranderen de globale vorm van de ster en zijn daarom moeilijk te detecteren.

Gaia heeft sterke niet-radiale aardbevingen gevonden in duizenden sterren. Gaia ontdekte ook dergelijke trillingen in sterren die nog maar zelden waren waargenomen. Deze sterren zouden volgens de huidige theorie geen aardbevingen moeten hebben, terwijl Gaia ze op hun oppervlak detecteerde.

“Starquakes leren ons veel over de sterren, met name hun innerlijke werking. Gaia opent een goudmijn voor enorme stellaire wetenschap”, zegt Connie Aerts van de KU Leuven in België, een lid van de Gaia-samenwerking.

stellaire DNA

Het materiaal waaruit sterren zijn gemaakt, kan ons vertellen over waar ze zijn geboren en hun volgende reis, en dus over de geschiedenis van de Melkweg. Met de publicatie van gegevens vandaag onthult Gaia de grootste chemische kaart van de melkweg in combinatie met 3D-bewegingen, van onze zonneomgeving tot de kleinere sterrenstelsels om ons heen.

Sommige sterren bevatten meer “zware metalen” dan andere. tijdens de[{” attribute=””>Big Bang, only light elements were formed (hydrogen and helium). All other heavier elements – called metals by astronomers – are built inside stars. When stars die, they release these metals into the gas and dust between the stars called the interstellar medium, out of which new stars form. Active star formation and death will lead to an environment that is richer in metals. Therefore, a star’s chemical composition is a bit like its DNA, giving us crucial information about its origin.

This image shows an artistic impression of the Milky Way, and on top of that an overlay showing the location and densities of a young star sample from Gaia’s data release 3 (in yellow-green). The “you are here” sign points towards the Sun. Credit: © ESA/Gaia/DPAC; CC BY-SA 3.0 IGO

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 larger distances. Gaia also identified stars that originally came from different galaxies than our own, based on their chemical composition.

“Our galaxy is a beautiful melting pot of stars,” says Alejandra Recio-Blanco of the Observatoire de la Côte d’Azur in France, who is a member of the Gaia collaboration.

“This diversity is extremely important, because it tells us the story of our galaxy’s formation. It reveals the processes of migration within our galaxy and accretion from external galaxies. It also clearly shows that our Sun, and we, all belong to an ever-changing system, formed thanks to the assembly of stars and gas of different origins.”

This image shows the orbits of the more than 150,000 asteroids in Gaia’s data release 3, from the inner parts of the Solar System to the Trojan asteroids at the distance of Jupiter, with different color codes. The yellow circle at the center represents the Sun. Blue represents the inner part of the Solar System, where the Near Earth Asteroids, Mars crossers, and terrestrial planets are. The Main Belt, between Mars and Jupiter, is green. Jupiter trojans are red. Credit: © ESA/Gaia/DPAC; CC BY-SA 3.0 IGO, Acknowledgements: P. Tanga (Observatoire de la Côte d’Azur)

Binary stars, asteroids, quasars, and more

Other papers that are published today reflect the breadth and depth of Gaia’s discovery potential. A new binary star catalog presents the mass and evolution of more than 800 thousand binary systems, while a new asteroid survey comprising 156 thousand rocky bodies is digging deeper into the origin of our Solar System. Gaia is also revealing information about 10 million variable stars, mysterious macro-molecules between stars, as well as quasars and galaxies beyond our own cosmic neighborhood.

The position of each asteroid at 12:00 CEST on June 13, 2022, is plotted. Each asteroid is a segment representing its motion over 10 days. Inner bodies move faster around the Sun (yellow circle at the center). Blue represents the inner part of the Solar System, where the Near Earth Asteroids, Mars crossers, and terrestrial planets are. The Main Belt, between Mars and Jupiter, is green. The two orange ‘clouds’ correspond to the Trojan asteroids of Jupiter. Credit: © ESA/Gaia/DPAC; CC BY-SA 3.0 IGO, Acknowledgements: P. Tanga (Observatoire de la Côte d’Azur)

“Unlike other missions that target specific objects, Gaia is a survey mission. This means that while surveying the entire sky with billions of stars multiple times, Gaia is bound to make discoveries that other more dedicated missions would miss. 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 surroundings than we could’ve imagined,” says Timo Prusti, Project Scientist for Gaia at ESA.