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An Optical/IR Observational Study of Faint Cataclysmic Variables

微弱灾难变量的光学/红外观测研究

基本信息

批准号：
9819770
负责人：
Steven Howell
金额：
$ 22.5万
依托单位：
University of Wyoming
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1999
资助国家：
美国
起止时间：
1999-07-15 至 2002-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819770&HistoricalAwards=false
关键词：
Optical IR Observational Study Faint

项目摘要

ABSTRACTAST-9819770Howell, SteveDr. Howell proposes an extensive observational and theoretical investigation of cataclysmic variable (CV) stars. CVs consist of a close pair of interacting stars in which the primary is a white dwarf accreting from a cooler normal main sequence star. Typical orbital periods are less than 12 hours. Such binary pairs are important because they provide an evolutionary bridge between some types of massive white dwarf stars that cannot easily result from normal single star evolution and supernova, often use as distance indicators to other galaxies because they are so bright. Since they are evolving rapidly, CVs also provide useful constraints on the white dwarfs masses, which are otherwise very difficult to determine, and on theoretical models of mass exchange in close binaries. Dr. Howell intends to greatly improve the observational coverage of fainter, shorter period CVs in order to test the hypothesis that short period CVs are in fact the most common type. The observations will also provide a robust test of theoretical models that predict that orbital periods reach a minimum at about 2 hours. Additional IR spectra obtained will yield important information on the physical characteristics of the thin accretion disks as well as the often hidden stellar components in fainter pairs. The observing facilities available at the University of Wyoming's Infrared Observatory (WIRO), Red Buttes Observatory (RBO) and University of Florida Rosemary Hill Observatory (RHO) will provide most of the photometric light curves and infrared spectroscopy.

摘要-9819770Howell, Steve 博士。豪厄尔提出对灾变变星（CV）进行广泛的观测和理论研究。 CV由一对紧密相互作用的恒星组成，其中主恒星是一颗白矮星，是从一颗较冷的正常主序恒星吸积而成的。典型的轨道周期小于 12 小时。这样的双星对很重要，因为它们在某些类型的大质量白矮星和超新星之间提供了进化桥梁，这些白矮星不容易由正常的单星演化产生，超新星通常用作其他星系的距离指示器，因为它们非常明亮。由于它们正在迅速演化，CV 还为白矮星质量（否则很难确定）以及紧密双星中质量交换的理论模型提供了有用的约束。 Howell 博士打算大大提高较暗、较短周期 CV 的观测覆盖范围，以检验短周期 CV 实际上是最常见类型的假设。这些观测结果还将为预测轨道周期在大约 2 小时达到最小值的理论模型提供有力的检验。获得的附加红外光谱将产生有关薄吸积盘的物理特征以及通常隐藏的较暗对恒星成分的重要信息。怀俄明大学红外天文台 (WIRO)、红山天文台 (RBO) 和佛罗里达大学罗斯玛丽山天文台 (RHO) 的观测设施将提供大部分光度曲线和红外光谱。