Discovery of a disk-collimated bipolar outflow in the proto-planetary nebula IRAS 17106-3046

We report the discovery of a collimated bipolar outflow emerging from a vis ible disk around the proto-planetary nebula IRAS 17106-3046. The radius of the disk, estimated to be 2500 AU at a distance of 4 kpc, is too large for it to be a Keplerian disk created by accretion. The radial intensity profil e of the disk suggests that it is consistent with an expanding torus. In co ntrast to the open-end, butterfly-like lobes commonly seen in bipolar plane tary nebulae, the lobes of IRAS 17106-3046 have pointed ends, suggesting a recently formed jet breaking out of the lobes. IRAS 17106-3046 therefore co uld represent the earliest stage of the bipolar-shaping process during the transition from an asymptotic giant branch star to a planetary nebula.