A Disk Shadow around the Young Star ASR 41 in NGC 1333

We present images of the young stellar object ASR 41 in the NGC 1333 star-forming region at the wavelengths of Hα and [S II] and in the I, J, H, and K bands. ASR 41 has the near-infrared morphology of an edge-on disk object but appears an order of magnitude larger than typical systems of this kind. We also present detailed models of the scattering and radiative transfer in systems consisting of a young star surrounded by a protoplanetary disk and the whole system being embedded in either an infalling envelope or a uniform molecular cloud. The best fit to the observed morphology can be achieved with a disk of ≈200 AU diameter, immersed in a low-density cloud (≈2 × 10-20 g cm-3). The low cloud density is necessary to stay below the submillimeter flux upper limits and to preserve the shadow cast by the disk via single scattering. The results demonstrate that ASR 41 is probably not inherently different from typical edge-on disk objects and that its large apparent size is due to the shadow of a much smaller disk being projected into the surrounding dusty molecular material.