This refers to the discovery that the Milky Way galaxy has a cluster of stars located at its outer edge that actually originated from another galaxy and was taken in by the Milky Way's gravitational pull.
This discovery was made by analyzing the movements and properties of stars in the Milky Way's outer regions. Astronomers were able to identify a distinct group of stars that did not originate from the Milky Way but were instead pulled in from a smaller galaxy.
The star cluster, known as Gaia-Enceladus, originated from a smaller galaxy that collided and eventually merged with the Milky Way billions of years ago.
This discovery is significant because it provides evidence of the Milky Way's growth through the process of galactic cannibalism, where larger galaxies absorb smaller ones. It also sheds light on the history and evolution of our galaxy.
Studying this star cluster can help us better understand the formation and evolution of galaxies, as well as the dynamics of galactic interactions. It can also provide insight into the distribution and movement of stars within the Milky Way.