Open AccessThe planetary nebula K 1‐2 and its binary central star VW Pyx
Author(s) -
Exter K. M.,
Pollacco D. L.,
Bell S. A.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06505.x
Subject(s) - physics , planetary nebula , astrophysics , common envelope , nebula , star (game theory) , subdwarf , binary star , accretion (finance) , stars , protoplanetary nebula , astronomy , binary system , binary number , white dwarf , arithmetic , mathematics
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 ∼ 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 ∼ 11 000 K and T O ∼ 16 000 K with log n e ∼ 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.