Their analysis also allows for the reconstruction of the amount of dust between a stellar source and Earth – just like dust reddens the sunlight at sunset or sunrise, cosmic dust reddens starlight in a characteristic way. The group also developed algorithms that assign parameter values for temperature and chemical composition to both single and binary stars in the Gaia catalogue. This is where Bailer-Jones's group at the Max Planck Institute for Astronomy is making a mark – the group was instrumental in developing the "Gaia classification machine", which uses statistical techniques to assign likely object classes to sources detected by Gaia. They also provide information about object classes, indicating to users whether a given source is a star, galaxy, or quasar. For one, they are providing astrophysical parameters for many of their sources – such as temperatures or indicators of chemical composition ("metallicity" in astronomy-speak) of stars. In order to facilitate this kind of astronomical research, and to make it easier for astronomers to access the data they need for specific analysis tasks, Gaia is publishing more than just their basic observational data. Just as a country-wide database of age, living conditions, income, family size, and other information allows researchers to understand different aspects of a country's population, so Gaia data allows astronomers to gain an understanding of different classes of astronomical objects, from stars to galaxies. In effect, given the data it produces and the sheer number of objects observed, Gaia is creating the most complete cosmic census yet. © ESA/Gaia/DPAC unter Lizenz CC BY-SA 3.0 IGOīut as the new data release, dubbed DR3, makes abundantly clear, the impact of Gaia data goes far beyond distance measurements and their consequences. (You can reproduce the same geometric effect by giving a "thumbs up", extending your arm forward, and then alternately closing one eye and the other – you should see how your thumb seems to "jump" relative to the more distant background.) Gaia's previous distance measurements have had a significant impact on astronomical research from mapping nearby stars to determining the expansion rate of the universe as a whole.
Gaia's main task was and is to determine accurate distances for billions of stars, using the so-called parallax method – based on the fact that, as the Earth makes its yearly orbit around the Sun, stars that are closer to Earth will shift their positions slightly relative to stars that are further away. The data set also includes contributions by the Gaia group at the Max Planck Institute for Astronomy, led by Coryn Bailer-Jones: astrophysical parameters derived from the observed data as well as object classifications that will make it easier for astronomers to use Gaia data in their research. The data set will be more extensive than previous versions notably, for the first time, optical spectra for 220 million astronomical objects will be published along with position and brightness data.
GAIA ASTROMETRY MISSION FULL
Now, on 13 June 2022, Gaia is releasing the third full data set of its mission. The observatory in question is ESA's Gaia satellite, and the data it is producing amounts to numbers – numbers for stellar positions, distances, the brightness of sources in different filter bands with variations over time, all of this for billions of stars, and millions of other astronomical objects. But one of the most productive astronomical observatories ever does not generally produce images, yet has led to over 6000 published papers with more than 150 000 citations. Given impressive images like those produced by the Hubble Space Telescope, it is no wonder that most people associate astronomical research with ever more detailed images of ever more distant astronomical objects.
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