On masses and ejection of planetary nebulae around PG 1159 stars

缺H的PG 1159恒星是理解后AGB演化的罗塞塔石碑。在它们最热的演化阶段，它们显示出白色矮星的形成：核燃烧接近尾声，引力效应将进一步主导它们的演化。两个事实使它们成为检验进化论的理想依据：首先，27颗已知的PG 1159恒星中有7颗是行星状星云;其次，大约每隔一颗PG 1159星星就有一个相关的行星状星云。我们提出了一个详细的检查，这些成像和光谱，以调查可能的中央恒星的质量和周围的星云，电离结构的星云，显示其喷射的时间依赖性之间的关系，和化学成分的星云。

The H-deficient PG 1159 stars are rosetta stones for the understanding of post-AGB evolution. At their hottest stage of evolution, they display the formation of white dwarfs: the nuclear burning is close to its end and gravitational effects will further dominate their evolution. Two facts make them ideal to check against evolutionary theory: firstly, 7 out of 27 known PG 1159 stars are pulsators; secondly, about every other PG 1159 star has an associated planetary nebula. We propose a detailed examination of these by imaging and spectroscopy in order to investigate a possible relation between the masses of central stars and their surrounding nebula, the ionization structure of the nebulae which displays the time-dependence of their ejection, and the chemical composition of the nebulae.