  The majority of stars are part of gravitationally bound stellar systems, such
as binaries. Observations of protobinary systems constrain the conditions that
lead to stellar multiplicity and subsequent orbital evolution. We report
high-angular resolution observations of the circumbinary disk around [BHB2007]
11, a young binary protostar system. The two protostars are embedded in
circumstellar disks that have radii of 2 to 3 astronomical units and probably
contain a few Jupiter masses. These systems are surrounded by a complex
structure of filaments connecting to the larger circumbinary disk. We also
observe accretion and radio jets associated with the protobinary system. The
accretion is preferentially onto the lower-mass protostar, consistent with
theoretical predictions.
