Migration of stars

Astronomers, led by Maria Bergemann from the Max Planck Institute for Astronomy, have investigated a small population of stars in the halo of the Milky Way Galaxy, finding its chemical composition to closely match that of the Galactic disk. This similarity provides compelling evidence that these stars have originated from within the disk, rather than from merged dwarf galaxies. The reason for this stellar migration is thought to be theoretically proposed oscillations of the Milky Way disk as a whole, induced by the tidal interaction of the Milky Way with a passing massive satellite galaxy.