Collaborative Research on Study of Halo Cataclysmic Variables

激变变星（Cataclysmic Variables，CV）是一种恒星系统， 以突然的亮度变化为特点。 其中包括新星 和类新星变星 所有的CV都是近距离双星， 由一个紧密的物体组成，通常是一个白色矮星，和一个红色的 星星。 CV被发现之间的磁盘和晕人口 银河系中的恒星 主要研究者 *（PI）建议观察照片- 从光谱和光谱上看，有40到50个CV是候选人 我们银河系的晕圈成员 首席 观测工具将是二维电荷耦合器件 （CCD），这将允许准确的光度研究，尽管 物体的极度模糊 这项研究的目的是 确定晕轮CV的轨道和物理特性， 与星系盘CV的数据进行比较。 这个观测项目和其他CV系统的结果 已经在文献中应该提供关于年龄， 化学成分和母体种群影响形成 尤其是CV 私家侦探们希望 能够在关于这些特性的相互冲突的理论之间做出选择， CV的形成。 该提案是三个相同提案之一，每个提案都有其 由三名主要研究员提交的自己的预算 不同的机构。 另外两名私家侦探是 行星科学研究所（NSF提案8914866）和约瑟夫 哥伦比亚大学的帕特森（8916995）。

Cataclysmic variables (CVs) are stellar systems that are characterized by sudden brightness changes. They include novae and nova-like variables. All CVs are close binary stars, consisting of a compact object, usually a white dwarf, and a red star. CVs are found among the disk and the halo population of stars in our Galaxy. The Principal Investigators* (PIs) propose to observe photo- metrically and spectroscopically 40 to 50 CVs that are candidate members of the halo population of our galaxy. The chief observing tool will be two-dimensional charge-coupled devices (CCDs), which will allow accurate photometric studies despite the objects' extreme faintness. The goal of this research is to determine the orbital and physical properties of halo CVs and to compare them with data of galactic disk CVs. The results of this observational program and of other CV systems already in the literature should provide information on how age, chemical composition, and parent population affect the formation of binary stars and, in particular, CVs. The PIs expect to be able to choose between conflicting theories on the properties and formation of CVs. This proposal is one of three identical proposals, each with its own budget, submitted by Principal Investigators (PIs) from three different institutions. The other two PIs are Steven Howell of the Planetary Science Institute (NSF Proposal 8914866) and Joseph Patterson of Columbia University (8916995).