Our Galaxy’s disk is warped, and that warp is dynamic. Here, Poggio et al. measure the rate of precession of the Galaxy’s warp using a large sample of giant stars. Rather than primordial, the rate of precession indicates that the Milky Way acquired its warp during a recent or even ongoing encounter with another galaxy.
- E. Poggio
- R. Drimmel
- A. Spagna
