Point-symmetry and the double planetary nebula kjpn 8

We present recent results of two topical problems on dynamical evolution of Planetary Nebulae (PNe) wherebinary nuclei, stellar rotation and magnetic elds play relevant roles. Namely, point-symmetry and multiple,collimated outows. Firstly, for point-symmetric morphologies, MHD models considering a s...

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Detalhes bibliográficos
Autores: M. Bryce, G. García Segura, J. A. López, J. Franco, L. F. Miranda, L. F. Rodríguez, W. Steffen, J. Meaburn, R. Vázquez
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2002
País:México
Recursos:Universidad Michoacana de San Nicolás de Hidalgo
Repositório:Redalyc-UMSNH
OAI Identifier:oai:redalyc.org:57112040
Acesso em linha:https://www.redalyc.org/articulo.oa?id=57112040
Access Level:Acceso aberto
Palavra-chave:Física, Astronomía y Matemáticas
SA 2
237)
ISM: JETS AND OUTFLOWS
PLANETARY NEBULAE: INDIVIDUAL (KJPN 8
Descrição
Resumo:We present recent results of two topical problems on dynamical evolution of Planetary Nebulae (PNe) wherebinary nuclei, stellar rotation and magnetic elds play relevant roles. Namely, point-symmetry and multiple,collimated outows. Firstly, for point-symmetric morphologies, MHD models considering a steady misalignmentof the magnetic collimation axis with respect to the symmetry axis of the bipolar wind outow are shown tosuccessfully reproduce for the rst time many of the morphologies that are observed. We compare the case ofthe bipolar PN Sa 2-237 with model results. Secondly, we discuss the origin of the extraordinary nebula KjPn 8.A substantial portion of the objects that go through the PN stage are expected to have binary nuclei, whichmay largely inuence the stellar evolution process during and after the PN phase. Depending on the separationand mass ratio of the components, phenomena such as cataclysmic variables, symbiotic objects and novae mayeventually be formed. In these cases, the mass ratios of the binary cores are far from unity and consequentlythe components evolve with widely di erent time scales. In contrast, ground-based multifrequency and HSTobservations indicate that in KjPn 8 we may be witnessing the case where two distinct and consecutive bipolarplanetary nebulae-like events have been detected simultaneously, most probably originating from a binary coreevolution with components of very similar mass having evolved nearly in parallel. In this case, KjPn 8 may bea rare object in our Galaxy and the rst ever detected of this class.