The Transition from Evolved Star to Planetary Nebula: An Observational Study

哈里特·迪纳斯坦博士将使用几种观察技术 来解决恒星如何经历转变的问题 从晚期红巨星转变为行星状星云， 白色矮星。 这一短暂的进化过程是 恒星生命史的转折点，但它仍然不是很好 明白 Dinerstein博士将调查并确定 周围的大规模剩余中性信封的性质 行星状星云的电离核心 最近的研究表明， 这些信封的存在，并说明了使用光学 和红外光谱来确定它们的参数。 数据 中性材料数量和分布对于 任何关于质量损失和行星状星云的综合图片 形成过程 Dinerstein博士还将研究进化的双相情感障碍 星云，这代表了即将到来的阶段 一个可辨认的行星状星云的外观。 通过组合 在几个波长的观测结果，Dinerstein博士将 能够确定这些结构的一般几何形状， 找到主要的质量和排放成分。 的比较 不同发展阶段的目标应明确 进化的进程通过这种短暂的和转化的 恒星演化的阶段。

Dr. Harriet Dinerstein will use several observational techniques to address the question of how stars undergo the transformation from late stage red giants into planetary nebulae and ultimately white dwarfs. This transitory evolutionary episode is a crucial turning point in stellar life histories, yet it is still not well understood. Dr. Dinerstein will investigate and define the properties of the massive residual neutral envelopes around the ionized cores of planetary nebulae. Recent work has demonstrated the presence of these envelopes and illustrated the use of optical and infrared spectroscopy to determine their parameters. Data on the amount and distribution of neutral material are essential to any comprehensive picture of the mass loss and planetary nebula formation process. Dr. Dinerstein will also study evolved bipolar nebulae, which represent the phase immediately preceding the appearance of a recognizable planetary nebula. By combining results of observations at several wavelengths, Dr. Dinerstein will be able to determine the general geometry of these structures and locate the main mass and emission components. The comparison of objects at different stages of development should clarify the evolutionary progression through this transient and transforming stage of stellar evolution.