Over 1.8 billion stars: Gaia’s atlas of the sky even bigger and more precise

ESA has released Gaia Early Data Release 3 (EDR3) and once again provides science and the general public with the most accurate atlas of the Milky Way. The data from the Gaia space telescope are particularly accurate and, according to the researchers involved, will set the standard for studying the structure of our Milky Way for decades.

The first part of the third dataset now contains measured values ​​for over 1.8 billion celestial bodies, including over 330,000 in the widest vicinity of our sun (up to 100 parsecs or 326 light years). This number alone is 100 times larger than Wilhelm Gliese’s catalog of nearby stars, one of the earlier standards.

By far the largest sky catalog

The Gaia Space Telescope was launched in 2013 and is currently perhaps the most important observatory in space and continuously scans the starry sky with a gigapixel camera. Using parallax measurements, it can accurately determine the position of countless stars in its path around the sun and, over time, their relative motion.

Over time, the data not only becomes more precise, but more and more objects can also be added to the catalog. The first collection, published in 2016, contained measurement data on about a billion stars, in 2018 it was almost 1.7 billion, now there are over 100 million more again. The data serves as the basis for a wide variety of studies in nearly all areas of astrophysics.

For the release of the first part of the third dataset (the full set is expected to follow in 2022), ESA highlighted some results that were made possible by this. Thus Gaia made possible the new census of the larger neighborhood of our sun, in which there are consequently more than 330,000 celestial bodies. It should be 92 percent of all objects in this area, the researchers write. Gaia also collected accurate data on the movement around the Milky Way for nearly 75,000 stars from this collection, which allows for predictions about their future orbits. Over the next 500 million years, they will therefore separate significantly.

Additionally, the solar system has been determined to orbit 0.23 nanometers per second faster in the Milky Way galaxy every second. The orbit of our solar system is therefore about 115 kilometers wider each year, scientists explain based on data from Gaia.

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Gaia is expected to collect data until 2025, about 850 million objects per day, which is equivalent to 20 gigabytes of data. The celestial catalog thus created is open not only to researchers and scientists, but also to anyone interested, such as amateur astronomers. Largely unnoticed by the public, it has long been responsible for a true revolution in astrophysics.

(mho)