Detection of stellar earthquakes resembling tsunamis on Earth
Scientists have discovered that stars are subjected to earthquakes like the ones we experience on earth that are so strong that the "tsunami-like" movements make them change their shape.
Scientists at the University of Cambridge were able to detect these "stellar earthquakes", known as non-radial oscillations, in thousands of stars by the European Space Agency's Gaia mission.
Astronomers came to this unexpected discovery with the most detailed survey of the Milky Way from the Observatory's data - which includes new and improved details of almost two billion stars in the Milky Way, about 1% of the total number in the Galaxy.
When assembled together, they form a "DNA map", which is a multidimensional visual image of asteroids, planets, stars and galaxies, and helps to identify the most habitable corners of our galaxy.
The map provides the largest-ever catalog of information about stars in the Milky Way
, including chemical compositions, stellar temperatures, colors, masses, ages, and the speed at which stars move toward or away from us (radial velocity).
One of the most surprising discoveries that emerged from the new data was that the Gaia observatory was able to detect stellar earthquakes - small movements on the surface of a star - that changed the shapes of stars, something for which the observatory was not originally created.
Previously, the Gaia mission found radial oscillations that cause stars to periodically swell and shrink, while maintaining their spherical shape.
But Gaia has now also detected other vibrations that astronomers have described as "more like large-scale tsunamis". These non-radial oscillations change the overall shape of the star and are therefore difficult to detect.
Connie Aerts of the Catholic University of Louvain in Belgium, a member of the Gaia program
, said: "stellar earthquakes teach us a lot about stars, especially their inner workings. The Gaia mission opens a gold mine of Astrophysics for massive stars".
And the substances that make up the stars can tell us about the place of their birth, their subsequent journey, and, accordingly, about the history of the Milky Way galaxy.
With the third release of data, the Gaia mission revealed the largest chemical map of the galaxy combined with three-dimensional movements, from our solar neighborhood to the smaller galaxies surrounding us.
And some stars contain more "heavy metals" than others. During the Big Bang,
only light elements (hydrogen and helium) were formed. And all the other heavier elements, which astronomers call metals, are built inside the stars.
When stars die, these minerals are released into interstellar gas and dust called the interstellar medium, from which new stars form.
Active star formation and death will lead to a more mineral-rich environment, so the chemical composition of a star is somewhat similar to DNA, which gives astronomers important information about its origin.
And scientists, relying on Gaia data, can see that some stars in our galaxy are made up of primordial matter, while others, like our sun, are made up of matter enriched by previous generations of stars.
And the stars that are closer to the center of our galaxy and its level are richer in minerals than the stars at greater distances.
The Gaia observatory also identified stars that originally came from galaxies different from ours, based on their chemical composition.
"The release of the main data from Gaia not only allows astronomers to determine the distances and movements of about two billion stars in our galaxy, but also gives detailed measurements of the physics and chemistry that make up a large number of these objects for the first time,"said Dr. Nicholas Walton, a scientist from the Institute of astronomy at the University of Cambridge.
Using this amazing database, we can build a comprehensive picture of the Milky Way and delve into its incredible history of formation, seeing first-hand evidence of both violent interactions in the past with other galaxies, and internal episodes of intense star formation along its spiral arms.
This new version of the data creates a detailed information Bank, which essentially acts as a DNA map that allows us to understand the stellar population of our galaxy, trace its past, present and future.
The Gaia observatory reveals information about 10 million variable stars, mysterious interstellar macromolecules, as well as quasars and galaxies beyond our cosmic ocean.
It is worth noting that the Gaia observatory is located about 1.5 million kilometers (930 thousand miles) from Earth, and carries two telescopes to document the Galaxy
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