What can be expected from the new data from Gaia Satellite?

The Gaia satellite was launched in 2013 1.5 million kilometers away from the Earth, in the direction of the sun and to scan space. Its main goal is to measure the position, distance, and motion of about two billion stars in the Milky Way. But it has other strings of bows, and its optics has focused on objects in the solar system up to a very bright quasar billions of light-years away from our star.

This June 13, 2022, from 10 a.m., ESA 3 will release the contentM The catalog (DR3) relates to the results of data analysis obtained over a period of 34 months between July 25, 2014 and May 28, 2017. One of the first overviews (EDR3) was already unveiled in December 2020 with astrometric and photometric measurements of 1.8 billion space objects in our galaxy. “Gaia Data has unveiled a new world and we will gain more accuracy and categorization with the results of this next batch.“Delighted Franোয়াois Mignard, from Observatory de Provence, and Gaia, scientific manager in France.

“Third dimension of space velocity”

DR3 will bring in a lot of new data, especially with almost all the objects in the catalog and many astrophysical parameters like temperature, gravity or even the abundance of chemical elements for 500 million of them. Gaia has also made it possible to measure the radial velocity of 34 million stars, i.e. the speed or distance from the Sun to them. “It’s a great jump that finally brings the third dimension of space motion“Emeritus and Catherine Turan, pioneers in space astronomy, have been explained by the Observatory de Paris-PSL. The other two dimensions measured are the speed of rotation and the tangent motion, such as the angular displacement of a star in the celestial sphere.”There will be another great innovation among the millions of Spectra publications received by RVS [le Radial Velocity Spectrometer] And two spectrophotometers, BP and RP, from Gaia“The astrophysicist added.

Guy’s various observation techniques. Credit: ESA.

Spectrophotometry will make it possible to classify objects with the properties of the surface and to establish the relationship between their color and their dynamic properties.“So much new information that will lead to numerous scientific publications. Thousands of articles have already appeared since the DR1 (in 2016), DR2 (in 2018) and EDR3 in 2020 spread. They’ve made it possible to represent it. The Milky Way Which has never been possible before: in 3D and color, but to detect all the stars around the Sun, to determine the acceleration of the solar system’s barikent, to detect signs of collisions between Milky Way billions of years ago and another galaxy and much more.

Among the innovations in this catalog is information on more than 800,000 non-simple objects, most of which are binary stars, a body made up of two stars, one of which may be a companion star. Type, a white dwarf, a neutron star or even a black holeAlain Jorisen, an astronomer at the Free University of Brussels and a member of the Belgian team of the DPAC Consortium (Data Processing and Analysis Consortium), has been underlined.

Follow the live broadcast of the 3rd Gaia Catalog from the Nice Observer de Provence on Monday, June 13, 2022 at 10am.

DPAC, which is also the cornerstone of the Gaia mission: it brings together 450 scientists, software developers and data processing experts. The goal is to process a huge flow of data from a satellite that represents the largest amount ever processed in the history of astronomy, about one petabyte (or 1 million billion bytes!). For this, DPAC is divided into 8 units, each responsible for a specific area of ​​the data analysis and reduction process and then their publication. A huge undertaking that explains why publications are shared in catalogs published almost every two years. DR4 is thus expected to be delivered by 2025 and the final release (which has not yet been officially scheduled) should be delivered by 2030.

Small solar system bodies, exoplanets and quasars

If Milky Way’s stars are Gaia’s main target, the telescope that scans the entire sky is also interested in a nearby neighbor: the Andromeda Galaxy, whose photometric survey will be published. And farther away are about 2.9 million galaxies and 1.9 million quasars, these active galactic nuclei hosting a supermassive black hole at their center, for which we will have new information. Finally, “We will also discover for the first time the details of the solar system, the moon and the small bodies of the asteroidsFranোয়াois Mignard adds.

Not less than 155,000 of them, which is the closest to the Earth that could threaten the dwarf planet Pluto. For each feature of brightness, color or composition. More than enough to occupy the experts for many years. Science and the future Gaia will be back in more detail soon on some aspects of the catalog.

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