PRECISION MEASUREMENT OF STELLAR SIZES AND CIRCUMSTELLAR MATERIAL WITH 10 MICRON INTERFEROMETRY AND NARROW FREQUENCY BANDWIDTHS

伯克利红外空间干涉仪是一个独特的系统的三个1.65米的望远镜位于山。威尔逊天文台它的基线范围从4米到大约75米，分辨率为20毫弧秒。该系统采用0.2/cm带宽的外差检波，所得信号可经滤波得到任意窄的谱宽。最近增加的第三台望远镜使相位闭合测量的精度达到了1度，这使得对强度模式（包括不对称性）的傅立叶分析几乎可以完成。将继续使用干涉仪对演化的晚型恒星进行观测。这些恒星的大小和选择相关的功能（周围的尘埃分布和不对称性，水蒸气信封等）。窄带宽的能力将允许周围气体的原子和分子光谱线被避免或选择产生，除其他特性外，可靠和现实的恒星尺寸。观测将跟踪Mira变星大小随相位的变化，并检查Mira和红巨星可能的球形度偏差。以前用干涉仪进行的研究已经显示了晚型恒星周围尘埃云的运动以及云与球对称的偏差。对这些变化的研究将继续下去，以提供有关恒星周围尘埃云运动的信息，并从这些信息和多普勒测量结果中确定距离。这里的工作将为年轻科学家提供培训。（博士后研究员）和学生（2名研究生和本科生），他们将有实践机会学习光学，电子学，计算机控制系统，数据分析，科学的解释。干涉测量和仪器是天文学界的两个高度优先领域，下一代鳄鱼建造者的教育对该领域的持续成功至关重要。

ABSTRACTThe Berkeley Infrared Spatial Interferometer is a unique system of three 1.65-metertelescopes located at the Mt. Wilson Observatory. Its baselines range from 4 toapproximately 75 meters and it is capable of 20 milliarcsecond resolution. The systemuses heterodyne detection with a bandwidth of 0.2/cm and the resulting signals can befilters to obtain arbitrarily narrow spectral widths. The recent addition of a third telescopehas allowed phase closure measurements to an accuracy of 1 degree, which allows nearlycomplete Fourier analysis of intensity patterns, including asymmetries.An observing program of evolved late-type stars will be continued using theinterferometer. The sizes of such stars and select associated features (surrounding dustdistributions and asymmetries, water vapor envelopes, etc.) will be directly measured.The narrow bandwidth capability will allow the atomic and molecular spectral lines ofsurrounding gas to be avoided or selected yielding, among other characteristics, reliableand realistic stellar sizes. The observations will follow the changes in size of prominentMira variable stars as a function of phase and examine possible departures fromsphericity of Miras and red giants. Previous studies with the interferometer have shownmovements of dust clouds surrounding late-type stars as well as deviations of the cloudsfrom spherical symmetry. Studies of these variations will be continued to provideinformation on the motion of dust clouds around stars, and from this and Dopplermeasurements, also a determination of distances.The work here will provide training for young scientists (a postdoctoral researchassociate) and students (2 graduate students as well as undergraduates) who will havehands-on opportunities to learn optics, electronics, computer control systems, dataanalysis, and scientific interpretation. Interferometry and instrumentation are two areas ofhigh priority for the astronomical community and the education of the next generation ofinstrument builders is critical the field's continued success.