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

RUI：遵循变异性——AGB后恒星和原行星状星云的特性和演化的关键

• 批准号: 1413660
• 负责人: Bruce Hrivnak
• 金额: $ 25.97万
• 依托单位: Valparaiso University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1413660&HistoricalAwards=false
• 关键词: RUI; Following; Variability; Key; Properties

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.

数十亿年来，类似于太阳的恒星演化形成红巨星，最终弹出外壳，形成行星状星云（PNe）。 行星状星云通过返回恒星内产生的物质来创造全新的恒星，在星系的化学演化中发挥着重要作用。 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，仅持续几十万年。 该提案的目标是研究处于这个过渡阶段的物体的基本物理特性，这些物体被称为原行星状星云（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，正在从渐近巨星分支 (AGB) 恒星过渡到 PNe。 该提案将继续并扩展对我们自己的星系以及附近的大麦哲伦星云星系中的 AGB 后恒星和 PPNe 进行光度和径向速度测量的现有计划。 光度曲线、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，恒星脉动模型将用于约束PPNe的质量和光度。 最后，该项目将调查 PPNe 的二元性程度及其对 PNe 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大量和广泛的机会。 该项目将通过在 PI 所在机构校园内的天文台举办的开放日向公众传达其结果。 PI 将继续进行社区和专业讲座，并将研究结果纳入这些演示中。