Fundamental Properties of Nearby Northern and Southern Stars

构成我们星系的恒星的特征大致是从观测到的邻近恒星的特性中推断出来的。这是我们可能期望最完全了解的样本，直到最微弱的恒星，并有最好的观测数据。事实上，许多离我们最近的恒星缺乏基本的测量，比如颜色、光谱类型，尤其是距离，而且许多新的天体还没有被发现。伊安娜博士的项目侧重于提供这些基本数据，并通过三角视差法确定距离来扩大附近恒星的样本，该方法强调从南半球进行CCD观测。他的计划包括一些已知最暗淡的恒星，几颗褐矮星和亚矮星，这些恒星来自我们银河系中最古老的恒星群。他的调查还将发现双星，其质量将被确定。该观测计划将有助于完成对太阳附近恒星的普查，阐明亮度和质量分布函数的暗端形式，并有助于我们对恒星群的形成和演化的理解。

Ianna, PhilipAST-9820711The characteristics of stars populating our galaxy are broadly inferred from the observed properties of the nearby stars. This is the sample we might expect to be known most completely, down to the very faintest stars possible, and to have the best observational data. In fact, many of the nearest stars lack basic measurements such as colors, spectral types, and especially distances, and many new objects are yet to be discovered. Dr. Ianna's program focuses on providing these basic data and on expanding the sample of nearby stars through determination of distances by the trigonometric parallax method emphasizing CCD observations from the southern hemisphere. His program includes some of the faintest known stars, several brown dwarfs, and subdwarfs, stars from the oldest populations in our galaxy. His surveys will also discover binary stars, for which masses will be determined. The program of observations will help to complete the stellar census of the solar neighborhood, clarify the form of the faint end of the luminosity and mass distribution functions, and contribute to our understanding of the formation and evolution of stellar populations.