Hubble Space Telescope Imaging of the Circumstellar Nebulosity of T Tauri

Short-exposure Planetary Camera images of T Tauri have been obtained using broadband filters spanning the wavelength range 0.55-0.80 μm. The optically visible star lies very close to an arc of reflection nebulosity. The arc's northern arm extends approximately 5" from the star, while its southwestern arm appears brighter and extends only 2". The arc shows an approximate symmetry along an axis toward the west-northwest, the direction of Hind's Nebula and the blueshifted molecular outflow. The morphology of the reflected light is similar to models of scattered light within an illuminated, axisymmetric outflow cavity in a circumbinary envelope, viewed ≈ 45° from the outflow axis. However, our model images do not successfully account for the amount of limb brightening that is seen. No optical counterpart to the infrared companion is seen to a limiting magnitude of V = 19.6, which suggests A_V > 7 mag toward this source. There is no evidence for an optical tertiary, to a limiting ΔV = 5.1 mag fainter than the primary, at the position where such an object has been previously reported