The European Space Agency's
GAIA (Global Astrometric Interferometer for Astrophysics) mission continues to help scientists compile a star map and catalog of our galaxy, the Milky Way. At the moment, the number of objects listed in the catalog is already 1.7 billion. In order to add new stars to the map, scientists have spent about 22 months. The data of each object includes information about the coordinates of the star, distance, motion characteristics. In addition to the stars, GAIA also tracks asteroids in the solar system.
A preliminary analysis of all these data allowed scientists to understand how stars behave in the galaxy, which can provide insight into the evolution of the Milky Way. “The observational data collected by GAIA makes it possible to clarify the very basis of astronomy,” said Gunter Hasinger, head of science at ESA.
He also added that the mission of GAIA is very ambitious, and its successful implementation depends on the coordination of the actions of hundreds and thousands of organizations and specialists. All this is necessary to handle huge databases of complex data. The long-term goals of the project are to increase the amount of scientific knowledge and the implementation of even more interesting scientific missions in the near future.
GAIA was launched in December 2013, and began work a year later, after performing a series of necessary tests and checks. The first press release, including data from studies of stars in the Milky Way, was published in 2016. The paper said that scientists were able to catalog more than 2 million stars, including such characteristics as distances and motion information. The release can be found
at this link .
The new press release includes data based on an analysis of GAIA observations from July 25, 2014 to May 23, 2016. As mentioned above, the number of stars is not millions or tens of millions, but more than 1.7 billion stars, and their location and other characteristics are specified. In addition to coordinates, specialists now have information on the brightness and color of more than half a million variable stars, which can serve as peculiar beacons for future star travelers. Now, these stars help to more accurately assess the coordinates of their "neighbors". Information was obtained on the temperature of the surface layers of 100 million stars. In addition, the data of more than 14,000 known asteroids, including the characteristics of their orbits, are refined. In future releases, members of the GAIA mission will present data on a much larger number of asteroids.
To notice and study some stars is technically as difficult as assessing the location and condition of a one-euro coin lying on the surface of the moon.
The new catalog lists parallax and speed for more than 1.3 billion stars. For another 0.4 billion specifications are being specified. Thanks to the parallax data, experts will be able to estimate the distance to the stars that are of most interest to scientists. Interestingly, about thirty years ago, the Milky Way's star catalog began to be the precursor GAIA, the Hipparcos satellite. Then with its help more than 118,000 stars were studied.
450 data scientists and software specialists work together on the GAIA data analysis. It should be noted that without modern hardware and software to carry out such work would be simply impossible.
In the catalog there is data not only about the stars, but also other objects - both the solar system and the galaxy. Special attention is paid to quasars, since they are even better than variable stars will help orient themselves in space.
The optical scheme of the telescope consists of two mirror telescopes with the size of the primary mirrors (M1, M'1) 1.46 by 0.51 meters. In total, each telescope has 6 mirrors. In this case, both telescopes project an image into one focal plane, and the separation of images is assigned to digital processing. For some photosensors, a set of diffraction gratings is additionally used. For scanning, the telescope combines several types of rotations.
Gaia is designed for five years of operation. The satellite orbit is designed so that for about 6 years not to fall into the region of shadow or penumbra from the Earth, since even a short eclipse will lead to loss of power supply and significant heat shock.