RUI: An Observational Study of Proto-Planetary Nebulae

通过“行星状星云核”（PPN）阶段，红超巨星向白矮星的演化发生得非常快，因此是恒星演化中最不为人所知的阶段之一。这也是一个非常重要的阶段。正是在这段时间里，一颗恒星将许多中等质量的元素（如碳、氮和氧）送回星际空间，新一代的恒星最终再次形成。PI提出了一个程序，首先，确定新的候选PPN，其次，确定它们的光谱能量分布。这些信息最终将被用来推断年龄的分布，从而对它们在这个短暂阶段的演化过程中所具有的特性进行敏感的“普查”。这项研究需要大量的数据分析和简化，最好是在专用计算机上。该合同将支持购买一台工作站来执行这些任务。

The evolution of red supergiant stars to white dwarfs through the "planetary nebula nucleus" (PPN) stage occurs very quickly and is therefore one of the most poorly understood stages of stellar evolution. It is also a very important stage. It is during this time that a star returns many of the intermediate-weight elements (such as carbon, nitrogen, and oxygen) into interstellar space, from which new generations of stars are eventually formed once again. The PI proposes a program first, to identify new PPN candidates and, second, to determine their spectral energy distributions. This information will be used ultimately to infer the distribution of ages and thereby to do a sensitve "census" of their properties as they evolve through this brief phase. This study requires a great deal of data analysis and reduction, preferably on a dedicated computer. This award will support the purchase of a workstation to perform these tasks.