Samuel Ryan (Institute of Astronomy, University of Cambridge)

Our galaxy the Milky Way is the result of billions of years of galactic evolution by consuming the smallest of dwarf galaxies to the massive Gaia-Sausage. This evolution, though, is not just from a past age, but is happening in front of our eyes with the Sagittarius Stream and The Magellanic Clouds. Thanks to the European Space Agency’s Gaia satellite, we are now in the midst of a revolution in our understanding of galactic archaeology, with two billion stars being observed by Gaia since its first data release in September 2016. In this seminar, I will introduce the new field of galactic archaeology and the revolution that Gaia has inaugurated, moving to my current research on the Gaia-Sausage and how its impact on the Milky Way changed its fate.