Modelling the Milky Way with Gaia-TGAS

I summarize two recent projects involving the Gaia-TGAS data. Firstly, I discuss a detection of a lack of disc stars in the Solar neighbourhood with velocities close to zero angular momentum. We use predictions of this effect to make a measurement of the Solar rotation velocity around the Galactic centre, and also of R ₀. Secondly, I discuss a detection of a group of stars with systematically high Galactic rotation velocity. We propose that it may be caused by the Perseus arm and compare the data with simulations.