Ref: ASTROimport-769

Symmetry and Asymmetry in "born again" Planetary Nebulae

Kimeswenger, S. ; Zijlstra, A. A. ; van Hoof, P. A. M. ; Hajduk, M. ; Lechner, M. F. M. ; van de Steene, G. C. ; Gesicki, K.

published in Asymmetrical Planetary Nebulae IV, pp. 17 (2007)

Abstract: While in the past spheroidicity was assumed, and still is used in modeling of most nebulae, we know now that only a small number of planetary nebulae (PNe) are really spherical or at least nearly round. Round planetary nebulae are the minority of objects. In case of those objects that underwent a very late helium flash (called VLTP or "born-again" PNe) it seems to be different. The first, hydrogen rich PN, is more or less round. The ejecta from the VLTP event is extremely asymmetrically. Angular momentum is mostly assumed to be the main reason for the asymmetry in PNe. Thus we have to find processes either changing their behavior within a few hundred to a few thousands of years or change their properties dramatically due to the variation of the abundance. They most likely have a strong link or dependency with the abundance of the ejecta.

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Royal Observatory of Belgium > Astronomy & Astrophysics
Science Articles > Non-refereed Articles

 Record created 2016-07-01, last modified 2016-07-01