Observational population studies of cataclysmic variables -The golden era of surveys

摘要

We review the properties of the currently known CV popula-tion from an accountants point of view. In particular, it is examined to what extent different selection mechanisms (variability, X-ray emission, colours, spec-troscopic properties) affect the observed CV orbital period distribution. Large-scale surveys provide homogeneously selected CV samples, for which observa-tional biases can in principle be modelled. Such samples will eventually provide the essential observational input for an improved understanding of CV evolution, and we highlight the impact of several completed and on-going surveys.