A circumstellar disk in a pre-main-sequence binary star

New high-resolution images of HK T Tauri B, the companion to the 10(6) yr old classical T Tauri star HK Tauri A, show it to be surrounded by an optically thick, edge-on circumstellar disk that extends to a radius of at least 50 AU. The images were taken using a modified speckle technique to achieve a linear resolution of 8 AU. The disk is strikingly coherent, showing no evidence of any strong perturbation by the primary star. The disk is illuminated by the central star, and it hides the star from direct view. The small changes in vertical thickness with wavelength require a dust + gas mass greater than or similar to 10(-3) M.. The relative position angles of the disk and the binary suggest that the disk probably does not lie in the plane of the binary orbit.