[ad_1]
What is Gaia? The goal of the ESA mission, launched on December 19, 2013, is none other than to produce a three-dimensional map of all the astronomical objects that can be detected by the satellite’s 1000-megapixel camera, an impressive average of three million stars per hour. The observations are so accurate that Gaia could track a few centimeters of motion for objects that are as distant as the Moon. An international team of scientists generates scientifically usable results from this huge amount of observational data. This computation, the iterative solution of a huge system of equations with 10 billion unknowns, has kept the supercomputers of several European research institutes busy since 2015. Among them, TU Dresden’s high-performance computers have been in high demand by the team from the Prof. Klioner to produce the numerous interim solutions that have finally led to decisive improvements of the new Gaia products.
The excellent quality of these results allowed the Dresden scientists to detect a very interesting phenomenon: the acceleration of our solar system. In astronomy, it has long been known that such an acceleration causes a slow and apparent displacement of all astronomical objects, which should become evident as a global pattern in measured movements. However, for nearby stars, this effect is completely superimposed on the complex structure and dynamics of our Galaxy.
Only a precise measurement of extremely distant astronomical objects, so-called quasars, could reveal this acceleration effect. These extremely bright cores of distant galaxies are considered to be almost fixed in the sky, which is why they are used in astronomy as landmarks.
The Dresden team has identified approximately 1.6 million Gaia objects as quasars, which will now be published as Gaia’s own celestial frame of reference. These quasars clearly show the predicted motion pattern of extremely small acceleration, which, according to the results produced in Dresden, is 0.23 nanometers per second squared. This is the first time this detection has been achieved using optical observations. Professor Klioner explains:
“Measuring the acceleration of the solar system with a relative accuracy of 7 percent is a very important scientific achievement and, at the same time, it is a compelling demonstration of the quality of the new data. The acceleration measured by Gaia shows a close agreement with expectations. theoretical and provides important information on the motion of the Solar System in the gravitational field of our Galaxy “.
The next publication of the Gaia catalog is scheduled for the first half of 2022. Given the data published so far, we can certainly expect considerable research of the highest level in the future. Since its release in April 2018, the second version of the Gaia catalog has generated an average of five publications per day!
Preparations for the fourth Gaia catalog have already begun in Dresden, which will be published in 2025. Observation data for this catalog will await the Dresden Gaia team from January 2021 at the latest, including both of its very special challenges that need to be mastered and its scientific treasures that must be recovered.
###
Details on the German event
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of press releases published on EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
.
[ad_2]
Source link
