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ANDROMEDA CRASH TRIGGERED A MASS GALACTIC MIGRATION 2 BILLION YEARS AGO
The influx of stars into our neighbouring galaxy reflects a violent event in the Milky Way’s past
Reported by Robert Lea
The Andromeda Galaxy, also known as Messier 31
A stronomers have discovered new evidence that Andromeda, the galaxy next door to our own, grew by merging with another galaxy.
The event triggered a mass migration of stars into the galaxy. This event suggests that the migration of stars to Andromeda – also known as Messier 31 – and the galaxy’s growth history is very similar to that of the Milky Way. That means the findings have implications for our understanding of both galaxies. The evidence came in the form of observations of the individual motions of almost 7,500 stars in the inner halo of Andromeda, showing these stars had begun their lives as part of another galaxy that merged with Andromeda around 2 billion years ago.