Multipolar Bubbles, Point-Symmetry, and Jets in Dying Stars

Abstract

The imaging of young planetary and pre-planetary nebulae (YPNe and PPNe) with unprecedented high angular resolution and dynamic range using the Hubble Space Telescope (HST), has shown that most of these objects are highly aspherical, with complex multipolar morphologies. The complexity, organization and symmetry of the morphological structures has radically changed our understanding of the mass-loss processes during late stellar evolution. We have proposed that high-speed collimated outflows or jets operating during the late AGB and/or early post-AGB evolutionary phase play a fundamental role in shaping PNe. We present here new results from our multi-wavelength program of imaging and spectroscopy of YPNe and PPNe that support this model, and describe a parallel effort to infer the properties of the fast outflows using numerical simulations.