2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. FIRST EVIDENCE OF A PRECESSING JET EXCAVATING A PROTOSTELLAR ENVELOPE

We present new, sensitive, near-infrared images of the Class I protostar, Elias 29, in the Ophiuchus cloud core. To explore the relationship between the infall envelope and the outflow, narrowband 1–0 S(1), Brg, andH2 filters were used to image the source with the Wide-Field Infrared Camera on the Hale 5 m telescope andKcont with Persson’s Auxiliary Nasmyth Infrared Camera on the Baade 6.5 m telescope. The source appears as a bipolar, scattered light nebula, with a wide opening angle in all filters, as is typical for late-stage protostars. However, the pure emission-line images point to the presence of a heretofore undetected precessing jet. It isH2 argued that high-velocity, narrow, precessing jets provide the mechanism for creating the observed wide-angled outflow cavity in this source