A Measurement of Diffusion in 47 Tucanae

Using images from the Hubble Space Telescope Wide-Field Camera 3, we measure the rate of diffusion of stars through the core of the globular cluster 47 Tucanae using a sample of young white dwarfs identified in these observations. This is the first direct measurement of diffusion due to gravitational relaxation. We find that the diffusion rate $\kappa \approx 10-13$ arcsecond${}^2$ Myr${}^{-1}$ is consistent with theoretical estimates of the relaxation time in the core of 47 Tucanae of about 70 Myr.