European Space Agency (ESA)presented a very accurate and highly detailed map of the Milky Way, which shows the exact location and brightness of almost 1.7 billion stars. At the moment this is the most complete star catalog, which was created thanks to the work of the Gaia space telescope.
The Gaia apparatus was created by ESA and placed into orbit inthe end of 2013. The tool works in the optical range and measures the proper motions of the stars (displacements of stars on the celestial sphere, which are caused by their movement relative to the solar system), as well as parallax - changes in star coordinates, which is associated with a change in the observer position due to the Earth's rotation around the Sun. The combination of these data allows us to find out the distance to the stars and understand how they are distributed in our galaxy.
360-degree panorama of the parallax of stars, as Gaia sees it
As a result of the first 14 months of observation, scientistsWe received the first data set, on the basis of which in 2016 a highly detailed map of our galaxy was created, taking into account the features of more than 1.1 billion stars. The second data set covers the observation period from July 2014 to May 2016 and already contains 1.3 billion stars. In addition, Gaia measured the brightness and color of 1.7 billion stars, as well as changes in these characteristics for 500 million other objects. The new catalog also includes data on the temperature of about 100 million stars.
Radial velocity map of stars. Red shows objects moving away from the Sun, and blue shows objects approaching it.
Approximately 7 million stars were measuredradial velocities, which allowed us to find out which trajectories they move relative to the center of the Milky Way. This information is necessary to find out the weight of our galaxy, as well as the distribution (and possibly the properties) of dark matter, which, according to scientists, together with dark energy, makes up 95 percent of the mass of our Universe.
Objects of research Gaia. From left to right: objects of the Solar system, neighboring stars, the Milky Way and its jumper, galactic halo and globular clusters, neighboring galaxies, distant quasars
Researchers have noticed that in the movement of stars,which rotate at about the same speed, there are some features. In future works, scientists are going to check whether they are associated with disturbances created by the jumper in the center of the Milky Way, which is a dense region of stars and interstellar gas, or is it somehow related to past mergers of the Milky Way with other smaller galaxies.
Gaia telescope also identified 75 ball orbitsclusters and 12 dwarf galaxies that revolve around the Milky Way. The operation of the telescope and the data obtained allow us to study the past of our galaxy and its surroundings. For example, the distribution of dark matter or the gravitational influence of other objects. In addition, the new data release contains the position of 14,099 known objects in the solar system, the bulk of which are asteroids.