Precision Models for a Reference Set of Mira Variables

米拉变星是一类特殊的变星，位于影响星系演化的几个重要物理过程的核心。它们在星系再循环过程中发挥着关键作用：随着时间的推移，它们将大部分物质返回星际介质，并强烈影响星系的外观。它们也非常明亮，是极好的距离指示器，这使它们成为绘制银河系分布的理想候选者。另一方面，它们是复杂的恒星，在不同的波长和时间尺度上呈现出非常不同的外观。这项提议将通过审查过去几年的大量档案数据，并将它们与多次空间飞行任务最近的观察结果结合起来，创建迄今为止最广泛的Mira变量参考集。将这些观测与最先进的建模工具相结合，该团队将为每颗恒星提供丰富的基本参数，如变化周期、辐射热通量、半径、质量、光度、有效温度、距离。除了对实地的重大直接影响外，拟议的工作还将产生重大的更广泛的影响：国际和平协会和共同国际和平协会都有长期接触当地主要是西班牙裔社区的记录，小组的其他成员积极教授为年轻妇女开设的STEM预科课程。这项研究将解决三个基本问题：(1)不同类型的MIRA的主要脉动模式是什么？(2)根据现有的光谱数据，相对于化学亚型和质量损失历史，周期-光度关系中的细微差别是什么？以及(3)在光球表面上和光球表面上发现的分子相的函数的详细大气行为是什么？大部分观测将从加州理工喷气推进实验室的Palomar试验台干涉仪(PTI)中提取，使用H和K波段。将使用最新的TESS数据，辅之以AAVSO和AFOEV的长期基线数据库来确定周期。辐射热通量将使用2MASS、COBE、MSX和WISE数据并通过对PTI数据的定制分析来确定。最后，将使用Gaia数据确定距离。额外的光度数据将使用专用的机器人20英寸望远镜以排队模式获得。将使用半径-温度建模工具来确定额外的参数。这一奖励反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Mira variable stars are a special class of variable stars that lie at the heart of several important physical processes affecting the evolution of galaxies. They play a critical role in the galactic recycling process: over time they return much of their material to the interstellar medium and they strongly affect the appearance of galaxies. They are also extremely luminous and are excellent distance indicators, which makes them ideal candidates to map out galactic distributions. On the other hand, they are complicated stars, which can appear very differently across different wavelengths and time scales. This proposal will create the most extensive reference set of Mira variables to date, by examining a vast amount of archival data spanning several years in the past and combining them with recent observations from multiple space missions. Pairing these observations with state-of-the-art modeling tools, the team will provide a wealth of fundamental parameters for each star, such as variability periods, bolometric fluxes, radii, masses, luminosities, effective temperatures, distances. Besides the substantial direct impact on the field, the work proposed will have significant broader impacts: both the PI and Co-PI have long track-records of outreach to their local, predominantly Hispanic communities, and other members of the team are active in teaching STEM preparatory courses for young women. This study will address three fundamental questions: (1) What are the dominant pulsation modes for the various types of Miras? (2) What are the nuances in the Period-Luminosity relationship with respect to chemical subtype and mass-loss history as traced though available spectroscopic data? and (3) What is the detailed atmospheric behavior as a function of phase of molecules found at and above the photospheric surface? Most of the observations will be extracted from the Caltech-JPL’s Palomar Testbed Interferometer (PTI) using H and K bands. Periods will be determined using recent TESS data, supplemented by the long-time baseline AAVSO and AFOEV databases. The bolometric flux will be determined using 2MASS, COBE, MSX and WISE data and by custom analysis of the PTI data. Finally, distances will be determined using Gaia data. Additional photometric data will be obtained in queue mode using a dedicated, robotic 20-inch telescope. A radius-temperature modeling tool will be used to determine the additional parameters.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.