Part of stars was found, contrary to expectations, moves to the center of the milky Way.
Astronomers have discovered in the milky Way stars, which probably came to him from another galaxy. The discovery was made during the search for ultra-fast stars. This is a rare class of stars, the speed of which can be tens of times larger than normal, informs Rus.Media.
Usually the stars revolve around the center of our Galaxy at a speed of about hundreds of kilometers per second, but scientists sometimes exceptions do happen. Superfast stars, whose existence first became known in 1988, can move at speeds over thousands of kilometers per second. It is believed that they are born near the galactic center, and then gradually displaced on the outskirts of the milky Way through the interaction with admisiune black hole. But now astronomers have found suns which, on the contrary, fly to the center of our Galaxy.
Tomasso Marchetti (Marchetti Tommaso) of Leiden University, together with colleagues analyzed the observed positions on the sky, parallax, proper motion and radial velocity of stars from the catalog received by the telescope Gaia. Based on these data, they constructed the distribution of speeds and distances for 7 million stars in the milky Way. Then astronomers began to look for objects whose speed would be so high that would allow them to leave the Galaxy. As a result, scientists were able to identify 125 candidates, of which only 20 could overcome the pull of the milky Way with a probability above 80 percent.
Because the sample was small, astronomers were unable to find bullet star (they are rare, today there are only about 20 such objects). Seven sites were traucki stars that were probably ejected from their normal orbits in the interaction with other bodies and is now moving at speeds that reach up to 700 kilometers per second. Moreover, they did not move from the center of the milky Way to its outskirts, and Vice versa. According to scientists, it can be “guests” from neighboring galaxies.
Astronomers believe that the stars could have come from the Large Magellanic Cloud, a dwarf galaxy located in 163 thousand light-years from us, or from some more distant galaxy. If this hypothesis is correct, studying them, researchers will be able to describe the mechanisms of star formation in other galaxies, and to determine whether supermassive black holes, as they usually provide luminaries such high speed.