A photo from open sources
The Gaia – European Southern Observatory project brings together a space telescope with a ground-based just-shift means of observation. And the ground system components showed excellent result even before receiving the first fruits of work space fellow.
Using the data of the “Very Large Telescope”, which is located in Chile, researchers led by Gerry Gilmore of Cambridge University (UK) showed that, judging by distribution of chemical elements in the galactic disk, our The galaxy first formed in areas adjacent to the core, and only then gradually swelled in all directions. First milky The path was much more compact, and only as it grew and absorbed neighboring galaxies, it expanded to its modern periphery. (Here and below are illustrations by Wikimedia Commons, Joe Parks, Gaia-ESO.) Massive stars, most often producing these or those elements, including magnesium, scatter it around their neighborhood in an explosion, which puts an end to their life cycle. Although it has long been known track the distribution of magnesium in various stars of the Galaxy for a long time failed. This time astronomers compared the contents magnesium in the so-called solar circle – that part of the galaxy, which is inside the orbit of the sun orbiting the center Milky Way. It turned out the following: the luminaries there are rich magnesium much more often than their analogues outside this circle. At outside of the circle, stars can be either metal rich or poor, but their average age is much less than inside the circle, and even with an overall high metallicity, they have less magnesium than luminaries as rich in heavy elements inside the “Solar circle. “Among other things, it turned out that the stars in the young ‘thin disk’ galaxies under 8 billion years old, almost all characterized by a similar degree of metallicity, regardless of whether they live seven or one billion years. Moreover, many of They are very rich in heavy elements. 
Photo from open sources That part of the Galaxy that lies inside The solar circle is definitely ancient and richer in magnesium. But stars older than 9 billion years, frequent for the so-called thick disk Galaxies smoothly “lose” in metallicity with age, and at the same time not one of those that crossed this line can boast an abundance of heavy elements. At the same time, separate luminaries of both disks can have a very different age, and it cannot be said that in “thick” or “thin” disk objects are concentrated only one groups. In the near future, these data will be significantly supplemented. observations of the Gaia space telescope. Study report will soon appear in the journal Astronomy and Astrophysics, and his preprint is available on arXiv website. Prepared by materials Cambridge University.
Alexander Berezin
Galaxy Time Milky Way Telescope
