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，与太阳类似的恒星进化成红巨星，最终喷出它们的外壳，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的角色，它将恒星内部产生的物质送回形成全新的恒星。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，只持续几十万年。这项提议的目的是研究在这个过渡阶段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察和技术来开展这项研究。PPNe是处于恒星演化后期的中等质量天体，由渐近巨星分支（AGB）恒星向PNe过渡。该提案将继续并扩展现有的agb后恒星和PPNe的光度和径向速度测量计划，这些恒星和PPNe位于我们自己的星系以及附近的大小麦哲伦星云星系。光度曲线、颜色测量和视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，恒星脉动模型将用于约束PPNe的质量和光度。最后，该程序将调查二值化的程度在PPNe和其对成形的影响。这个本科院校研究（RUI）项目将为新科学家的培训、文科生的教育和PI所在机构的科学基础设施提供大量广泛的机会。该项目将通过在PI所在机构校园的天文台举行的开放日向公众传达其结果。PI将继续举办社区和专业讲座，并将研究结果纳入这些演讲中。

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.