The Magnetic Field and Maser Structure in the Proto-Planetary Nebula IRAS 20406+2953

Our understanding of the morphological evolutionary path from AGB star to planetary nebula is still unclear; broadly speaking, we are faced with shaping models that primarily detail varying forms of binary evolution, and those which concentrate on the in uence of stellar magnetic fields. Here we report the detection and measurement of a magnetic field in the proto-planetary nebula IRAS 20406+2953. This is the second such object in which we have measured a field strength and shown that the magnetic energy density in the wind is an order of magnitude higher than the bulk mechanical energy density, suggesting that the magnetic field could be in uential in shaping the out ow.