Multiplicity among the young stars in Taurus

We have surveyed 28 young stars systems in the northern Taurus star-forming region, for multiplicity. Our observations, made by infrared lunar occultation and imaging techniques, can identify binaries in the angular separation range 0″.005-10″. Of the 28 systems, 11 are binaries and two are triples, giving an observed multiplicity of 1.5 stars per system. The binary frequency and distribution of separations are similar to those of the main-sequence F and G spectral-type stars. Stars that have detected companions and those without are indistinguishable in Ha equivalent width, indicating that stars with active inner disks are represented in both groups. The multiple systems are in general weaker 1.3 mm continuum emitters than the single stars, indicating that the large-scale disks in these systems are less massive. However, there are important exceptions so the evolution of disks in multiple systems is not clear.