LEAPS-MPS: A Systematic Investigation of Transient Behavior in RR Lyrae Variable Stars

LEAPS-MPS：对天琴座 RR 变星瞬态行为的系统研究

• 批准号: 2137787
• 负责人: Kenneth Carrell
• 金额: $ 10.55万
• 依托单位: Angelo State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2137787&HistoricalAwards=false
• 关键词: LEAPS; MPS; Systematic; Investigation; Transient

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). RR Lyrae stars are a class of variable star whose pulsations have a relatively straightforward relationship to their intrinsic luminosities. As such, these stars provide a ‘standard candle’ against which to measure distance throughout the galaxy (and even to other galaxies). Because of their role in setting distance scales throughout the universe, pulsations of RR Lyrae stars continue to be studied decades after the broad outline of the mechanism was first described. Any change in that understanding could have significant implications on other parts of astronomy. The team will study changes in the amplitude of the fundamental mode of pulsation, along with its first overtone, as well as non-radial pulsations on these otherwise radially pulsing stars. They will make ground-based spectroscopic observations while the TESS spacecraft conducts photometric observations of the same star, allowing real-time comparison. Undergraduate students, drawn from under-represented groups at a Hispanic Serving Institution, will be involved in all aspects of the research. The team recently discovered changes in the amplitude of the fundamental pulsation mode of the double-mode RR Lyrae star V338 Boo. The fundamental pulsation’s amplitude is found to change on the scale of many tens of days, while the first overtone’s amplitude remains constant. Further, other teams have recently discovered non-radial pulsations whose amplitudes also change on the scale of tens of days. The team will observe a set of RR-Lyrae stars to look for similar changes in pulsations, and will furthermore conduct co-incident observsations with the TESS satellite to compare real-time spectroscopic variations with photometric variations. The team will observe known RR Lyrae stars; the study of these modes and variations will inform astrophysical models of stellar interiors.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.

该奖项是根据2021年《美国救援计划法》（公法117-2）全部或部分资助的。 RR Lyrae恒星是一类可变恒星，其脉动与它们的内在亮度具有相对直接的关系。因此，这些恒星提供了一种“标准蜡烛”，可以在整个星系（甚至其他星系）中测量距离。由于它们在整个宇宙中的距离尺度上的作用，因此首先描述了该机理的广泛轮廓后，RR Lyrae星的脉动继续进行研究。这种理解的任何变化都可能对天文学的其他部分产生重大影响。该团队将研究搏动模式的放大器的变化，以及其第一个泛音，以及这些原本辐射的脉动恒星的非主脉冲。他们将进行地面光谱观测，而苔丝航天器进行同一恒星的光度观测，从而实时比较。来自西班牙裔服务机构代表性不足的团体的本科生将参与研究的各个方面。该小组最近发现了双模式RR Lyre Star V338 Boo的基本脉动模式的放大器的变化。发现基本的脉动放大器在数十天的规模上发生了变化，而第一个庞克的放大器仍然保持恒定。此外，其他团队最近发现了非主导脉动，其放大器也随着数十天的时间而变化。该团队将观察一组RR淋巴星，以寻找脉动的类似变化，并将与苔丝卫星进行共同观察，以比较实时光谱变化与光度变化。该团队将观察已知的RR Lyrae明星；对这些模式和变化的研究将为恒星内部的天体物理模型提供依据。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为是通过评估来获得支持的。

项目成果

Modulation of the Blazhko Cycle in LS Her

LS Her 中 Blazhko 循环的调制

• DOI: 10.3847/1538-3881/acc4ba
• 发表时间: 2023
• 期刊: The Astronomical Journal
• 作者: Wilhelm, Ronald;Carrell, Kenneth;Means, Hannah H.;Popowicz, Adam;Bernacki, Krzysztof;Frąckiewicz, Mariusz;Szczepański, Marek;Dustor, Adam;Lockett, Jaylon;Taylor, Jill
• 通讯作者: Taylor, Jill