UBVRI Photometric Standard Stars

这项研究项目的目标是增强、开发和发布微弱的标准恒星序列。长期需要在各种光学波长下具有已知强度和颜色的精确光度学标准恒星。使用这样的标准恒星，可以将不同研究人员对不同天象的亮度和颜色测量结果进行组合和相互比较。应用的例子包括校准天体的星等和颜色指数，以进一步了解恒星的演化、星团的年龄和距离，研究可变恒星，并定义通过我们的银河系，本星系组，直到宇宙边缘的距离尺度。在这里，兰道特博士将使用智利塞罗托洛洛美洲天文台的望远镜，完成新标准恒星的研制工作，这些恒星的亮度将比现有恒星暗约100倍。他还将在亚利桑那州的基特峰国家天文台开始开发下一组更暗的标准恒星。这些校准星是目前建造的、在建的和规划阶段的最大的陆基和天基光学探测器的整个组合所需要的，并将由它们使用。这个项目的总体目标是将校准序列扩展到更模糊的界限，这样解释的界限将是科学的，而不是校准的界限。

The goal of this research project is to enhance, develop, and publish faint standard star sequences. There is a long-term need for accurate photometric standard stars with known intensities and colors at a variety of optical wavelengths. Use of such standard stars permits the combination and inter-comparison of the brightness and color measurements of different celestial phenomena made by different investigators. Examples of uses include the calibration of magnitudes and color indices of celestial objects to further the understanding of stellar evolution, ages and distances of star clusters, studies of variable stars, and to define the distance scale through our Milky Way Galaxy, the local group of galaxies, and onward to the edge of the Universe. Here, using telescopes at the Cerro Tololo Interamerican Observatory in Chile, Dr. Landolt will complete the development of new standard stars that will be about 100 times fainter than those now available. He will also begin development of the next set of even fainter standard stars at the Kitt Peak National Observatory in Arizona. These calibration stars are needed for, and will be usable by the entire ensemble of the largest ground-based and space-based optical detectors, both presently built, those under construction, and those in the planning stage. The overall goal of this project is to extend the calibration sequences to fainter limits so the limits of interpretation will be scientific, and not those of calibration.