Binary CSPN and PN Abundances
A. Frankowski · AIP conference proceedings · 2005
Bipolar planetary nebulae (PNe) are often associated with high mass objects because of their metallicity, but there are numerous exceptions (including as many as 1/3 of all bipolars). On the other hand, it seems that the main requirement for this morphology is a binary companion. In this paper a possible connection of the exceptional cases to a specific binary evolution path is considered. © 2005 American Institute of Physics.