  When a circumbinary disk surrounds a binary whose secondary's mass is at
least $\sim 10^{-2}\times$ the primary's mass, a nearly empty cavity with
radius a few times the binary separation is carved out of the disk. Narrow
streams of material pass from the inner edge of the circumbinary disk into the
domain of the binary itself, where they eventually join onto the small disks
orbiting the members of the binary. Using data from 3-d MHD simulations of this
process, we determine the luminosity of these streams; it is mostly due to weak
laminar shocks, and is in general only a few percent of the luminosity of
adjacent regions of either the circumbinary disk or the "mini-disks". This
luminosity therefore hardly affects the deficit in the thermal continuum
predicted on the basis of a perfectly dark gap region.
