Scientists studied a group of stars located right outside our galaxy, the Milky Way. They found the stars’ chemical configuration is perfectly matching the chemical composition of the stars inside our galaxy. What is with these outside stars? Did they come for another place in space or did they remain behind Milky Way?
Aforementioned connection gives proof that those stars have started their “space trip” from within Milky Way. The basis of such a separation of stars is considered to be oscillations of the Milky Way galaxy as a complex, produced by a Milky Way satellite galaxy.
Those outside stars appear not to be aleatorily dispersed in the Milky Way’s vicinity. Many of them are arranged in enormous formations, known as clouds of stars. Even more, some of them are entirely surrounding the Milky Way.
The outside stars reveal information about Milky Way’s turbulent history
Astronomers have tried to study more the turbulent past of our galaxy by studying the characteristics shown by the stars that resided right outside our galaxy (also known as halo stars).
These halo stars formations have been explained as marks of the Milky Way’s turbulent history, being considered remains of the gravitational separation of the many galaxies which are believed to have collided with Milky Way, a long time ago.
Apparently, those stars’ location in the Milky Way halo and movements can provide scientists evidence of the initial track of the intruding satellite galaxy, while those stars’ chemical structure can show astronomers some information about the aspect of the satellite galaxy that hit Milky Way.
“We showed that (…) groups of stars in the galaxy (…) been ‘kicked out’ by an invading satellite galaxy. Similar (…) patterns may also be found in other galaxies,” according to Allyson Shefield, Ph.D. at LaGuardia Community College.
This study’s discoveries are really inspiring because they show that our galaxy’s dynamics are considerably more elaborated than earlier theorized and that a satellite galaxy has collided with Milky Way. The study was published in the journal Nature.