IN SEARCH OF HL TAURI

We present infrared polarimetric images that demonstrate that the T Ta uri star HL Tau is not seen in direct light at lambda less than or equ al to 2.2 mu m. The position of the intensity centroid moves monotonic ally southwest from V (0.555 mu m) through J (1.25 mu m) and H (1.65 m u m) to K (2.2 mu m) wave bands. Furthermore, the mean position of the J, H, and K polarimetric centroids-which marks the position of the il luminating source of extensive reflection nebulosity-is displaced simi lar to 1'' southwest of the position of the K-band intensity peak. Thi s offset is in the same direction as the offset between the K-band int ensity peak and the centroid of previously detected 3.6 cm emission. W e conclude that, at optical and near-IR wavelengths, all of the observ ed radiation is scattered light from the circumstellar nebula. Our pol arimetric images of HL Tau show a ''polarization disk'' at PA 134 degr ees and therefore support a model in which the projection of the equat orial plane of the protoplanetary disk is aligned at PA 134 degrees. T hese results reinforce the contention that HL Tau is younger and more deeply embedded than typical T Tauri stars.