The Evolution of Planetary Nebulae and Their Central Stars

在中等质量恒星的历史上，红超巨星将它们的外壳驱逐出去是一个关键时刻。被驱逐的外壳从恒星的热残余核心发出的光中发光，被称为“行星状星云”。残骸最终冷却成为一颗富含碳、氮、氧、氖等中间元素的白矮星。在这个为期三年的更新奖中，首席研究员（PI）将从各种分子的光线下的最新图像中研究星云的结构，以及由不同质量和初始恒星的化学丰度定义的原始白矮星的进化路径。预计这个小组将为我们理解恒星演化的这个关键时刻做出更大的贡献。

The expulsion of their envelopes by red supergiants is a crucial moment in an intermediate-mass star's history. The expelled envelope glows from the light of the hot remant core of the star and is called a "planetary nebula." The remnant eventually cools to become a white dwarf star enriched in intermediate elements such as C,N,O,Ne. In this three-year renewal award, the Principal Investigator (PI) will study both the structure of the nebulae from recent images in the light of various molecules and the evolutionary paths of the proto- white dwarfs defined by different masses and chemical abundances of the initial star. It is expected that this group will add to their already substantial contributions to our understanding of this critical juncture in stellar evolution.