The absolute calibration of Cepheid and Mira Period-Luminosity relations in the near-infrared

近红外造父变星和米拉周期-光度关系的绝对校准

• 批准号: 1211603
• 负责人: Lucas Macri
• 金额: $ 20.08万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1211603&HistoricalAwards=false
• 关键词: absolute; calibration; Cepheid; Mira; Period

The investigators will analyze observational time-series near-infrared data of variable stars in order to reduce uncertainties in the Hubble constant, which is used to determine the age of the universe. They will focus on variable stars that belong to eclipsing binaries in nearby galaxies and us stellar atmosphere models, in order to calculate accurate stellar radii. The calculated stellar radii and measured periods and magnitudes will be used to derive distances that will be incorporated in the extragalactic "cosmic distance ladder," from which an improved value of the Hubble constant can be derived. This work will have broader impacts in that it involve the participation of a graduate student from an underrepresented group, and the PI will give bilingual talks to the public and maintain a public website in Spanish.

研究人员将分析变星的观测时间序列近红外数据，以减少用于确定宇宙年龄的哈勃常数的不确定性。他们将专注于附近星系中属于日食双星的变星和我们的恒星大气模型，以计算准确的恒星半径。计算出的恒星半径、测量的周期和星等将被用来得出将被并入河外“宇宙距离阶梯”的距离，由此可以得出哈勃常数的改进值。这项工作将产生更广泛的影响，因为它涉及来自代表性不足群体的一名研究生的参与，国际和平协会将向公众进行双语讲座，并维持一个西班牙语公共网站。