Photo from Gaia’s Early Data Release 3 in 2020. Image: ESA/Gaia/DPAC (CC BY-SA 3.0 IGO). Acknowledgement: A Moitinho
Starquakes, stellar DNA and other unique insights have been detected in the latest data release from the ESA’s Gaia mission.
The latest “treasure trove” of data from the European Space Agency (ESA) Gaia mission contains new and improved details on nearly 2bn stars in the Milky Way.
The third data release (Gaia DR3) is likely to offer new insights into our galaxy and beyond, with details on chemical compositions, stellar temperatures, colours, masses and ages of stars.
Gaia was launched in 2013 to chart a three-dimensional map of the Milky Way and reveal the composition, formation and evolution of our galaxy.
With this latest data, Gaia has revealed the largest chemical map of the galaxy to date, from our solar system to smaller galaxies that surround ours.
When stars die, they release metals into the gas and dust between stars called the interstellar medium, where new stars are born. Because of this, a star’s chemical composition can be seen as its DNA, providing information about its origin.
The ESA hopes that astronomers can use the Gaia data to reconstruct the Milky Way’s structure and past evolution, to better understand the lifecycle of stars.
“Gaia’s chemical catalogue of 6m stars is 10 times larger than previous ground-based catalogues, so this is really revolutionary,” said Dr George Seabroke of University College London’s Mullard Space Science Laboratory.
“Gaia’s data releases are telling us where stars were located and how they are moving. Now we also know what a lot of these stars are made of.”
The latest data was collected between July 2014 and May 2017. It provides new insights into ‘starquakes’, stellar DNA and asymmetric motions.
It also contains the largest catalogue to date of binary stars, thousands of solar system objects such as asteroids and moons, and millions of galaxies and quasars outside the Milky Way.
“Unlike other missions that target specific objects, Gaia is a survey mission,” explained Timo Prusti, ESA project scientist for Gaia.
“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.”
The latest dataset surpasses the previous Gaia map released in 2018, which pinned down the positions of nearly 1.7bn stars with great precision.
By comparison, the first data release following Gaia’s launch at the end of 2013 captured data for just 2m stars.
Starquakes
In the previous surveys, Gaia found radial oscillations that cause stars to swell and shrink periodically, while keeping their spherical shape.
But in the new dataset, Gaia also spotted other vibrations described as more like “large-scale tsunamis”. These non-radial oscillations change the global shape of a star and are harder to detect.
But such tiny motions on the surface of stars – or starquakes – have been detected in thousands of stars by Gaia.
“Starquakes teach us a lot about stars, notably their internal workings,” Conny Aerts of KU Leuven said. “Gaia is opening a goldmine for ‘asteroseismology’ of massive stars.”
While gathering details on the deepest depths of space, the latest batch of data also provides a greater level of insight into our own solar system.
Based on an asteroid survey from the Gaia data, we have now detected around 155,000 asteroids and their orbits, which could potentially help prevent a future collision on Earth.
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