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，类似太阳的恒星演化成红巨星，最终弹出它们的外壳，形成行星状星云(PNE)。行星状星云通过返回恒星内部产生的物质来创造全新的恒星，在银河系的化学演化中扮演着重要的角色。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，只持续了数十万年。这项提议的目标是研究这一过渡阶段天体的基本物理性质，这些天体被称为原行星星云(PPNe)。该项目将使用各种观察和技术来开展这项研究。PPNe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恒星。该提议将继续并扩大现有的对我们银河系内以及附近的大小麦哲伦星云星系中的后AGB恒星和PPNe进行光度和径向速度测量的方案。光度学光曲线、颜色测量和径向速度的组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约束PPNe的质量和光度。最后，该计划将调查PPNe的二元化程度及其对PNE形成的影响。这个本科生研究机构(RUI)项目将为新科学家的培养、文科学生的教育以及PI机构的科学基础设施提供大量和广泛的机会。该项目将通过在国际和平机构总部校园的天文台举行的开放参观活动向公众公布其结果。该协会将继续举办社区和专业讲座，并将把研究成果纳入这些报告中。

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.