  Close pre-main-sequence binary stars are expected to clear central holes in
their protoplanetary disks, but the extent to which material can flow from the
circumbinary disk across the gap onto the individual circumstellar disks has
been unclear. In binaries with eccentric orbits, periodic perturbation of the
outer disk is predicted to induce mass flow across the gap, resulting in
accretion that varies with the binary period. This accretion may manifest
itself observationally as periodic changes in luminosity. Here we present a
search for such periodic accretion in the pre-main-sequence spectroscopic
binary UZ Tau E. We present BVRI photometry spanning three years; we find that
the brightness of UZ Tau E is clearly periodic, with a best-fit period of 19.16
+/- 0.04 days. This is consistent with the spectroscopic binary period of 19.13
days, refined here from analysis of new and existing radial velocity data. The
brightness of UZ Tau E shows significant random variability, but the overall
periodic pattern is a broad peak in enhanced brightness, spanning more than
half the binary orbital period. The variability of the H-alpha line is not as
clearly periodic, but given the sparseness of the data, some periodic component
is not ruled out. The photometric variations are in good agreement with
predictions from simulations of binaries with orbital parameters similar to
those of UZ Tau E, suggesting that periodic accretion does occur from
circumbinary disks, replenishing the inner disks and possibly extending the
timescale over which they might form planets.
