A Vast Stream of Flowing Stars Is Evidence of The Milky Way’s Violent History
Using data from the Gaia Milky Way mapping survey, astronomers have discovered a vast stream of stars that they believe are the remnants of a massive dwarf galaxy that got dragged into the galactic disc before being torn apart. They have called the stream Nyx, after the Greek goddess of night.
According to the standard model of the evolution of the Universe, galaxies grow by merging with and absorbing smaller galaxies – the accretion process. There’s actually loads of evidence of this occurring in the Milky Way: a number of streams have been identified that have been linked to dwarf galaxies and globular clusters disrupted by the galaxy’s tidal forces.
When you go outside and look at the sky on a clear night, it seems like nothing else could be as serene and peaceful. But many of those seemingly peaceful stars are evidence of a turbulent history – and now we’re learning to unlock their secrets.