An Optical/IR Observational Study of Faint Cataclysmic Variables

摘要-9819770豪厄尔，史蒂文博士。豪厄尔提议对激变变星进行广泛的观测和理论研究。CVS由一对紧密相互作用的恒星组成，其中的主要恒星是一颗白矮星，它是从较冷的正常主序星吸积而来的。典型的轨道周期不到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一座进化的桥梁，这些恒星不容易由正常的单星演化产生，超新星通常被用作到其他星系的距离指示器，因为它们太亮了。由于白矮星的演化速度很快，因此它们也对白矮星的质量以及近双星中质量交换的理论模型提供了有用的约束，否则这些质量很难确定。豪厄尔博士打算极大地提高对较弱、较短周期简历的观察覆盖面，以检验短周期简历实际上是最常见类型的假设。这些观测还将对理论模型进行强有力的测试，这些模型预测轨道周期在大约2小时左右达到最小。获得的额外红外光谱将提供有关薄吸积盘的物理特征的重要信息，以及通常隐藏在较弱对中的恒星成分。怀俄明大学的红外天文台(WIRO)、红帽天文台(RBO)和佛罗里达大学迷迭香山天文台(RHO)的观测设施将提供大部分光度学光曲线和红外光谱。

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.