  Recently, Freilich et al. [Science 329, 1182 (2010)] experimentally
discovered stationary states of vortex dipoles, pairs of vortices of opposite
circulation, in dilute Bose-Einstein condensates. To explain their
observations, we perform simulations based on the Gross-Pitaevskii equation and
obtain excellent quantitative agreement on the size of the stationary dipole.
We also investigate how their imaging method, in which atoms are repeatedly
extracted from a single condensate, affects the vortex dynamics. We find that
it mainly induces isotropic size oscillations of the condensate without
otherwise disturbing the vortex trajectories. Thus, the imaging technique
appears to be a promising tool for studying real-time superfluid dynamics.
