High Galactic Latitude Cataclysmic Variables:

灾变变量（cv）是恒星系统，其特征是亮度突然变化。它们包括新星和类新星变量。所有的cv都是紧密的双星，由一个紧凑的物体组成，通常是一颗白矮星和一颗红星。cv是在我们银河系的星盘和星晕中发现的。首席研究人员* (pi)建议对40到50个cv进行光度测量和光谱学观测，这些cv是我们银河系晕族的候选成员。主要的观测工具将是二维电荷耦合器件（ccd），它将允许精确的光度研究，尽管物体非常微弱。这项研究的目的是确定晕cv的轨道和物理性质，并将它们与星系盘cv的数据进行比较。这个观测项目的结果和其他文献中已有的CV系统的结果应该提供关于年龄、化学成分和母星群如何影响双星形成，特别是CV的信息。pi期望能够在关于cv的性质和形成的相互矛盾的理论之间进行选择。*本建议书是三个相同的建议书之一，每个建议书都有自己的预算，由三个不同机构的首席研究员提交。其他两位pi是哥伦比亚大学的Joseph Patterson （NSF提案8916995）和华盛顿大学的Paula Szkody（8915445）。

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 Invsetigators* (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 PIs are Joseph Patterson of Columbia University (NSF Proposal 8916995) and Paula Szkody of the University of Washington (8915445).