HST/ACS Images of the GG Tauri Circumbinary Disk

We present early results from recent imaging of the GG Tauri binary star system and circumbinary disk at V and I passbands using the HST/ACS High Resolution Camera. Deep exposures combined with PSF subtraction provide images of the disk with higher contrast and resolution than were previously possible from the ground or HST. The disk, which appears as a ring due to tidal clearing, appears generally smooth, confirming the morphology seen in HST and recent adaptive optics observations. However, some small clumps or gaps in the ring are near the large gap that was previously identified as a shadow caused by material between the disk and stars. There is a subtle variation in brightness on the far side of the ring that suggests shadowing or perturbation of the disk. We confirm previous HST observations that show an arc of material located between the secondary component and ring. There is no evidence for the spokes seen in previous adaptive optics images that were interpreted as accretion streams. The ring near/farside contrast ratio is the same in both passbands, indicating that the scattering asymmetry properties of the dust are in line with those predicted by Close et al. (1998).