Abstract

The Born-again planetary nebulae Abell 30 and Abell78

Helge Todt (University of Potsdam)

M. A. Guerrero (Instituto de Astrofisica de Andalucia), S. J. Arthur (Centro de Radioastronomia y Astrofisica), W. P. Blair (Johns Hopkins University), Y.-H. Chu (University of Illinois at Urbana - Champaign), R. A. Gruendl (University of Illinois at Urbana - Champaign), W.-R. Hamann (University of Potsdam), L. Oskinova (University of Potsdam), J. A. Toala (Instituto de Astrofisica de Andalucia), M. Steffen (Astrophysikalisches Institut Potsdam), D. Schönberner (Astrophysikalisches Institut Potsdam)

The planetary nebulae Abell 30 and Abell 78 are rare born-again nebulae, which are believed to have undergone a very late thermal pulse, resulting in the ejection of hydrogen-poor material.

Born-again PNe are a rare phenomenon, only a few are known. It is really intriguing that in all cases the expansion of the hydrogen-poor ejecta is highly asymmetrical. Here we present new HST observations of the expansion of the ejecta in Abell 30 and Abell 78, and compare them to ~20 yrs older HST images.

Mode of presentation: poster