The influence of stellar evolution on planetary nebula formation

A discussion of how the fact that the central star evolves while the planetary nebula is forming affects the formation of the nebula. Numerical models point to a number of effects, such as more efficient shaping in the early phases and the formation of a surrounding shell. It is also found that for identical initial density distributions, quickly evolving (more massive) stars will form bipolar PNs and more slowly evolving stars will form elliptical PNs.Physics Dept. UMIST Manchester UK