Monthly notices of the royal astronomical society vol:341 issue:4 pages:1349-1359
New data are presented of the post-common-envelope binary VW Pyx and its associated planetary nebula (PN), K 1-2. The central star is found to be a single-lined (and possibly double-lined) spectroscopic binary and is a good candidate for a system in which the main-sequence secondary star is more massive than the subdwarf primary star. The old PN has a high excitation level and a measured electron temperature, T (O) similar to 17 000 K for an assumed log n (e) = 2.7 cm(-3) . The so-called 'jets' are found to be lower-ionization regions with T (N) similar to 11 000 K and T (O) similar to 16 000 K with log n (e) similar to 2.5 cm(-3) and with low, but fairly typical, PN abundances. We discuss possible histories for K 1-2 and the jets. However, there are still many unknowns in the study of accretion and jet formation for such PN binary central stars.