European space mission Gaia discovers migrating stars in our galaxy

The ESA telescope has discovered that there are stars in our galaxy that have migrated from another galaxy. This could be determined by the amount of heavy metals in the star, which can determine approximately where in the universe the star originated.

“Our galaxy is a beautiful melting pot of stars,” said Alejandra Recio-Blanco of the Côte d’Azur Observatory in France. “This diversity is extremely important because it tells us the story of how our galaxy was formed. It shows the migration processes within our galaxy and the attraction from external galaxies. It also clearly shows that our sun, and we, are all part of an ever-changing system, formed by the merging of stars and gas of different origin.”

In addition, the chemical make-up also tells researchers something about the concrete origin of a star. The closer to the center of the galaxy it originated, the more heavy metals a star contains. As a result, some stars contain more heavy metals than others. These metals are created by stars themselves, and do not come from the Big Bang. When a star dies, those substances are released into the interstellar medium and a new star can form from it.

Also “sterquakes” discovered

The Gaia telescope has made another surprising discovery, the press release said. Despite the fact that the telescope was not built to detect them, it has detected “starquakes”. These are tsunami-like movements that change the shape of a star, making them more difficult to distinguish normally. However, this unexpected discovery is important. “Starquakes teach us a lot about stars, especially about their internal processes. Gaia opens a gold mine for the ‘asteroseismology’ of massive stars”, says Conny Aerts of KU Leuven.

The ESA aims to use the Gaia mission to create a detailed map of the galaxy that will help astronomers better understand the history and structure of our galaxy.

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