Instrumentation for Global Time-Series Photometry

可能除了太阳外，脉动的白色矮星 探索恒星内部结构的最大潜力 通过实验手段。 丰富多样的振动波，可见 通过星星光度的变化， 在这些恒星中相互干扰， 星星的内部 干扰模式可用于 推断出每一波所穿过的物质的数量， 物质在星星中的分布 测定 这些原则，类似于几十年来使用的原则， 地球上的地震学家，现在正在应用于遥远的 星星第一次 白色矮星是最好的 候选人不仅因为他们表现出如此多的振动， 因为它们的周期足够短， 然后观察恒星的光线变化。 的 首席研究员在他的研究生涯中 设计和建造光度测量仪器， 光测量。 在之前的NSF奖项中，PI和他的 合作者发现，一个原型三通道光度计， 已经构建了（一个频道为节目星星，一个为一个 恒定的“标准”，一个是无星的“天空”）增加了 一个天文学家在一个晚上能花的时间 收集数据。 新的合同将允许PI建造两个 这个原型的便携式复制品 这些文书将 由他的同事运送到世界各地的观测点。 作为“观测活动”的一部分，目标恒星将被 在地球自转的同时被这些观测者一前一后地观测到。 在此活动之后，数据将被合并， 分析所需的几天的生产线 白色矮星的内部性质。

With the possible exception of the Sun, pulsating white dwarfs show the greatest potential for probing the interior structures of stars by experimental means. A rich variety of vibrating waves, visible at the surface by their change in the star's luminosity, are excited in these stars that interfere with one another throughout the star's interior. The pattern of interferences can be used to infer the amount of material each wave travels through, and hence the distribution of material through the star can ultimately be determined. These principles, similar to those used for decades by seismologists on the Earth, are now being applied to distant stars for the first time. The white dwarf stars are the best candidates not only because they exhibit so many vibrations but because their periods are short enough that many wave cycles can be followed by observing the stars' light variations. The Principal Investigator has spent most of his research career designing and building photometric instrumentation to make accurate light measurements. In a previous NSF award, the PI and his collaborators found that a prototype three-channel photometer they had constructed (one channel for the program star, one for a constant "standard", and one for a starless "sky") increases the amount of time during a night that an astronomer can spent actually collecting data. The new award will permit the PI to construct two portable duplicates of this prototype. These instruments will be transported by his colleagues to observing sites around the world. As part of an "observing campaign", target stars will then be observed in tandem by each of these observers as the Earth rotates. Following this campaign the data will be combined and a continuous several day-long string produced that is necessary for the analysis of interior properties of white dwarf stars.