T Tauri Multiple Systems

New high-resolution adaptive optics systems provide an unprecedentedly detailed view of nearby star forming regions. In particular, young nearby T Tauri stars can be probed at much smaller physical scales (a few AU) than possible just a decade ago (several tens of AU). Of major importance is closing the sensitivity gap between imaging and spectral surveys for stellar companions. This allows for 1) calibration of pre-main-sequence evolutionary tracks by obtaining accurate dynamical masses, 2) resolving confusion problems arising by placing unresolved systems in colour-magnitude diagrams, and 3) well defined and determined multiplicity fractions of young stellar systems, important for discriminating star formation scenarios. This article briefly reviews the current status of high resolution imaging of T Tauri multiple systems, and what we can expect to learn from them in the near future.