[Previous] | [Session 2] | [Next]
C. McCabe, A.M. Ghez (UCLA)
We present deep, high spatial resolution NICMOS/HST observations of the pre-main-sequence multiple star system, GG Tau, in three broad-band filters centered at 1.1, 1.6 and 2.0 micron. The images reveal a large ring surrounding the 0."25 binary, GG Tau A, which was originally detected in ground-based observations. The circumbinary disk, which extends from a radius of 125 to 300 AU (0."9 to 2."2) is detected with a signal-to-noise ratio approximately 100 times that of the ground-based measurements and has allowed us to study in detail both its unusual integrated colors and small scale structure. Although the disk is brighter on one side than the other, which can be accounted for in terms of forward and backward scattering, the disk has a red (1.6-2.0) color excess, which is unexpected for scattered light. A color-magnitude diagram for different resolution elements over the disk show that while extinction is present, this process alone cannot account for the observed red excess. We will discuss these and other results from the GG Tau NICMOS observations.