Galaxy's 'cannibalism' revealed

The vast Andromeda galaxy appears to have expanded by digesting stars from other galaxies, research has shown. When an international team of scientists mapped Andromeda, they discovered stars that they said were "remnants of dwarf galaxies". The astronomers report their findings in the journal Nature. This consumption of stars has been suggested previously, but the team's ultra-deep survey has provided detailed images to show that it took place