Close Companions to T Tauri Stars: Abundant and Perturbing
The results of a speckle imaging survey of T Tauri stars suggest that most, if not all, young low mass stars have companions. Furthermore, this survey reveals a distinction between the classical T Tauri stars (CTTS) and the weak-lined T Tauri stars (WTTS) based on the binary star frequency as a function of separation: the WTTS binary star distribution is enhanced at the closer separations. This suggests that close companions interact with the circumstellar disk material to effectively shorten the accretion time scale in multiple star systems. Recent follow up work has revealed orbital motion in the closest pairs (≤0."3), providing (1) evidence that these systems are indeed gravitationally bound and not the result of chance superpositions and (2) the basis for mass estimates that are necessary to distinguish between the various binary star formation mechanisms that have been proposed to date.
© 1994 Astronomical Society of the Pacific. Support for A.G.'s work is provided by NASA through grant HF-1031.01-92A awarded by the Space Telescope Science Institute which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA under contract NAS5-26555.
Published - 1994ASPC___56__221G.pdf