Launched into space in December 2013, Gaia began its observations on July 25, 2014 ; The result is a colossal volume of data collected, having already led to the publication of several catalogs. To date, more than 13,000 publications detailing the mission’s scientific results have been published : a record number !
A renewed vision of the Galaxy
Gaia has mapped the positions, distances, motions, changes in brightness, chemical composition and many other physical characteristics of stars, having observed them on numerous occasions, using its three instruments.
This has enabled it to achieve its main objective : to build the most detailed and accurate map of the Milky Way, showing, as no other mission has done before, what our home Galaxy must look like to an outside observer.
With the detection of multiple streams of ancient stars that merged with the Milky Way early in its history, followed by the discovery of evidence of an ongoing collision with the Sagittarius dwarf galaxy today, Gaia is rewriting the history of the Milky Way and making predictions about its future. Gaia is changing our view of the rotation of our galaxy’s central bar, the deformation of the disk, the detailed structure of the spiral arms and the interstellar dust near the Sun.
The satellite didn’t stop at just the stars in our galaxy. It has also scrutinized other objects : from nearby asteroids within the Solar System to galaxies far, far away from the Milky Way.
For example, Gaia has provided highly accurate orbits for over 150,000 asteroids and, with such high-quality measurements, has made it possible to discover possible moons around hundreds of them.
Gaia has also created the largest map of the sky for around 1.3 million quasars, the luminous, active centers of galaxies powered by supermassive black holes.
Gaia has also discovered a new type of black hole, including one with a mass almost 33 times that of the Sun, hidden in the Eagle constellation, less than 2,000 light-years from Earth. This is the first time that a stellar black hole of this size has been found in the Milky Way, and the discovery was made mainly by members of the Observatoire de Paris - PSL.
Two more catalogs to come
The end of satellite observations does not mean the end of scientific analysis. Many more discoveries are expected with the future Gaia DR4 and Gaia DR5 catalogs, concerning exoplanets or black holes, and an even more precise knowledge of the Milky Way.
As part of the Data Processing and Analysing Consortium (DPAC), Observatoire de Paris - PSL is making a significant contribution to this success story, with its major responsibilities in data processing and exploitation.
The data analysis work is set to continue, ever more intensively, in preparation for future publications based on much more data, even more varied, of even higher quality and covering even longer observation periods :
- the Gaia DR4 catalog, covering 5.5 years of observations, is expected at the end of 2026,
- and Gaia DR5, covering the full 10.5 years of observations, towards the end of the decade.
Stay tuned !
Gaia in a few key dates :
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