The Andromeda galaxy, the closest neighbour to our own Milky Way, has been growing by scooping up stars from smaller surrounding galaxies, a Canadian-led team of astronomers has found.
The astronomers found that Andromeda's gravity is pulling millions of stars away from its neighbour, the Triangulum galaxy, and calculate that in a few billions years, Andromeda could consume Triangulum completely.
The discovery comes as a result of the largest survey of a galaxy ever made, spanning nearly one million light years around Andromeda, a galaxy about 2.5 million light years away and visible to the naked eye. Triangulum is visible using a small telescope.
Alan McConnachie of the National Research Council's Herzberg Institute of Astrophysics led the international team of astronomers that included scientists from Canada, Australia, France, Germany, Britain and the United States.