RUI: Following the Variability - A Key to the Properties and Evolution of Post-AGB Stars and Proto-Planetary Nebulae

在数十亿年的时间里，与我们的太阳相似的恒星演化成红巨星，最终喷射出它们的外壳，形成行星状星云（PNE）。 行星状星云在星系的化学演化中扮演着重要角色，它将恒星内部产生的物质返回，创造出全新的恒星。 从红巨星到行星状星云的转变是恒星演化的一个重要但相对短暂的阶段，只持续了几十万年。 这项提议的目的是研究处于这一过渡阶段的被称为原行星状星云（PPNe）的物体的基本物理特性。 该项目将使用各种观测和技术来开展这项研究。PNe代表恒星演化后期的中等质量天体，它们正从渐近巨星分支（AGB）恒星过渡到PNe。 该提案将继续和扩展现有的光度和径向速度测量后AGB恒星和PPNe在我们自己的星系和附近的大麦哲伦星系和小麦哲伦星系的计划。 光度学光变曲线、颜色测量和径向速度的结合将允许直接确定恒星半径和光度等基本参数。 此外，恒星脉动模型将被用来限制PPNe的质量和光度。 最后，该计划将调查PPNe的二元性程度及其对PNE的形成的影响。本科院校研究（RUI）项目将为新科学家的培训，文科学生的教育以及PI机构的科学基础设施提供众多和广泛的机会。 该项目将通过在PI所在机构校园的观测站举行的开放日向公众通报其结果。 PI将继续提供社区和专业讲座，并将研究结果纳入这些演示文稿。

Over billions of years, stars similar to our sun evolve to form red giants that eventually eject their outer shells, forming planetary nebulae (PNe). Planetary nebulae play an important role in the chemical evolution of the galaxy by returning material created within stars to create brand-new stars. The transition from red giant to planetary nebula is an important but relatively short-lived stage of stellar evolution, lasting only a few hundred thousand years. The goal of this proposal is to study the basic physical properties of objects in this transition phase that are referred to as proto-planetary nebulae (PPNe). This project will use a variety of observations and techniques to carry out this study. PPNe represent intermediate mass objects in the late stages of stellar evolution that are transitioning from Asymptotic Giant Branch (AGB) stars to PNe. The proposal will continue and extend an existing program of photometric and radial velocity measurements of post-AGB stars and PPNe within our own galaxy and in the nearby Large and Small Magellanic Cloud galaxies. The combination of photometric light curves, color measurements, and radial velocities will permit the direct determination of fundamental parameters like stellar radius and luminosity. In addition, stellar pulsation models will be used to constrain the mass and luminosity of the PPNe. Finally, the program will investigate the degree of binarity in PPNe and its effect on the shaping of PNe.This Research in Undergraduate Institutions (RUI) project will provide numerous and wide-ranging opportunities for the training of new scientists, the education of liberal arts students, and the science infrastructure at the PI's institution. The project will communicate its results to the public through open houses held at the observatory on the campus of the PI's home institution. The PI will continue to give community and professional lectures and will incorporate the results of the research into those presentations.