Study of the Pulsations of the Semiregular Variable Stars

半规则变星脉动的研究

• 批准号: 0307281
• 负责人: J. Robert Buchler
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-15 至 2007-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307281&HistoricalAwards=false
• 关键词: Study; Pulsations; Semiregular; Variable; Stars

AST 0307281Buchler, J. RobertIrregularly pulsating stars stretch from the so-called W Vir type stars through the RV Tau and Semi-regular stars all the way into the long period Mira variable star region. In this project, a thorough, novel analysis of observational lightcurve data and a systematic numerical modeling survey of the pulsational properties of these stars is underway. These bright variable stars are playing an increasingly important role in the observational study of star clusters and dwarf galaxies where standard candles such as classical Cepheid variables may be rare. The goal is to extract unique, quantitative information from the irregular lightcurves. A test is also planned of the hypothesis that a single resonant mechanism is at the heart of the irregular pulsations of these stars. Further, the study will shed new light on the uncertain evolutionary status of these stars. New observational data, novel methods of analysis adapted from nonlinear dynamics, and progress in numerical convective hydrocodes lend this study a timely status.The project has a broader impact, because the techniques being developed are very useful in other research areas as well, ranging from astronomy to nonlinear dynamics to medicine. Thus two of the codes are being made user-friendly and publicly accessible: TIFRAN, the time-frequency analysis, that has medical applications as a diagnostic tool for speech disorders, otolaryngology and neurology among other things, and FLOWRECON, the flow reconstruction from a time-series with wide applications in nonlinear dynamics research. A popular website on radially and nonradially pulsating stars with audio and video is being constructed with the help of two undergraduate students. The teaching of the large undergraduate noncalculus physics class provides the investigator with the opportunity to bring astrophysics, and this research in particular, to the classroom.

Buchler，J.RobertAST 0307281Buchler，J.Robert不规则脉动的恒星从所谓的W Vir类型恒星延伸到RV Tau和半规则恒星，一直延伸到长周期Mira变星区域。在这个项目中，正在对观测光曲线数据进行彻底、新颖的分析，并对这些恒星的脉动特性进行系统的数值模拟调查。这些明亮的变星在星团和矮星系的观测研究中发挥着越来越重要的作用，在这些星系中，经典造父变星等标准蜡烛可能是稀有的。目标是从不规则的光照曲线中提取独特的、定量的信息。还计划对一种假设进行测试，即单一的共振机制是这些恒星不规则脉动的核心。此外，这项研究将为这些恒星不确定的进化状态提供新的线索。新的观测数据，适应于非线性动力学的新的分析方法，以及数值对流水码的进展，为这项研究提供了一个及时的状态。该项目具有更广泛的影响，因为正在开发的技术在其他研究领域也非常有用，从天文学到非线性动力学再到医学。因此，其中两个代码正在变得用户友好并可公开访问：TIFRAN是一种时频分析，其医学应用包括语音障碍、耳鼻喉科和神经学等；以及FLOWRECON，它是从时间序列重建的流，在非线性动力学研究中有着广泛的应用。在两名本科生的帮助下，一个关于径向和非径向脉动恒星的音频和视频网站正在建设中。本科生的大型非微积分物理课程的教学为研究人员提供了将天体物理学，特别是这项研究带到课堂上的机会。