The Evolution of Planetary Nebulae and Their Central Stars

在演化的后期阶段，大约1个太阳质量的恒星会抛出它们富含氢的外层包层，从而产生所谓的行星状星云(即不断膨胀的气态外壳，尽管有命名法，但它与行星无关)。剩下的恒星核心(即行星状星云的中心恒星)主要由氦组成，尽管也可能存在更重的元素。首席研究员建议研究行星状星云的形成及其中心恒星的演化，特别注意确定行星状星云的前驱恒星、星云和中心恒星中存在的元素丰度。这项工作将包括编制行星状星云的“谱线强度目录”。

During their late stages of evolution, stars of roughly 1 solar mass eject their outer, hydrogen-rich envelopes and thereby produce so-called planetary nebulae (i.e., expanding gaseous shells that, despite the nomenclature, have nothing to do with planets). The remaining stellar cores (i.e., the central stars of the planetary nebulae) consist predominantly of helium, though heavier elements may be present as well. The Principal Investigator proposes to study the formation of planetary nebulae and the evolution of their central stars, with particular attention paid to determining the elemental abundances present in the precursor stars, the nebulae, and the central stars of planetary nebulae. The work will include the compiling of a "Catalogue of Spectrum Line Intensities" of planetary nebulae.