Europe 1 with AFP 4:33 p.m., June 13, 2022
Positioned in space and equipped with two telescopes and an ultra-precise photographic sensor, Gaia delivered new data on nearly two billion stars in the Milky Way on Monday, with unprecedented precision making it possible to draw up a map of our galaxy, particularly alive.
"It's a fantastic day for astronomy, which opens the floodgates for new discoveries about the Universe and our galaxy", rejoiced Josef Aschbacher, director general of the European Space Agency (ESA) during the presentation of the results of Gaia, one of the agency's flagship scientific missions launched in 2013. This satellite, equipped with two telescopes and an extremely precise sensor, delivered new images of our galaxy on Monday, the Milky Way.
By far the largest group of Solar System objects in #GaiaDR3 are 154741 asteroids for which @ESAGaia has determined their orbits
Depending on their orbits one can distinguish different groups of #asteroids.
https://t.co/BOC31hti19pic.twitter.com/uQ8yzlOueC
— ESA Science (@esascience) June 13, 2022
The space observatory, stationed 1.5 million kilometers from Earth opposite the Sun, is in its third data harvest, intended to map our galaxy in all its dimensions, and thus understand its origin, its structure and its dynamics.
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A host of new details were released on Monday, such as these 220 million photometric spectra, which will make it possible to estimate for the first time the mass, color, temperature and age of stars.
As well as 2.5 million new chemical compositions, this "DNA" providing information on the birthplace of stars, and their journey through the galaxy.
A galaxy "much more turbulent than expected"
Surprise for scientists: Gaia spotted for the first time stellar "tremors", tiny movements on the surface of a star which modify its shape.
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The results, which gave rise to around fifty scientific articles in the process, paint the portrait of a galaxy "much more turbulent" than expected, told AFP the astronomer of the Observatory of the Coast. Azure.
"We thought it had reached a stationary state, gently turning on itself, like a fluid that is gently stirred with a wooden spoon. But not at all!", Develops François Mignard, scientific manager of the Gaia mission. for France.
"Traveling the past of the Milky Way"
Gaia's level of precision is such that it "will allow us to trace the past of the Milky Way over more than 10 billion years", added Anthony Brown, president of the international consortium DPAC, the ground processing chain of the data stream sent by Gaia.
The new catalog also offers unrivaled precision measurements for 156,000 asteroids in our solar system, breaking down the composition of 60,000 of them.
It will have taken five years to deliver this third catalog of observations spread from 2014 to 2017. And it will be necessary to wait until 2030 to obtain the final version, when Gaia will have finished scanning space, in 2025.