2000A&A...353L..25C

We report high resolution (1.1"x0.9") imaging of the proto-planetary nebula AFGL 2688 in the CO (J=2-1) line and the continuum at 230GHz, using the IRAM interferometer. The observations reveal with unprecedented detail the structure and the kinematics of the gas ejected by the star over the past few hundred years. Two distinct, high-velocity outflow directions are detected emerging from a central core of gas which surrounds the star: one is oriented north-south along the optical axis, the other is oriented east-west, close to the equatorial plane. We resolve the north-south and east-west outflows into a striking series of collimated, bipolar outflows. The tips of the outflows in the east-west direction correspond precisely to H₂ emission peaks seen in recent HST imaging at 2µm, providing direct evidence for the impact and likely shaping effects of jets on the nearly spherical AGB molecular envelope. These outflows exemplify the mechanism by which point symmetries are imprinted on the structure of planetary nebulae at early stages of their formation.