Survey of the Outer Galaxy

红巨星表现出一系列特性，这使得它们对研究我们银河系的遥远区域特别有用。它们本质上是明亮的，这使得在几千秒差距的距离内探测和处理它们成为可能。它们的数量足够用来寻找银河系的整体结构。安装在木曾施密特望远镜上的CCD相机被用来拍摄反银河系中心的图像。为了区分碳星和M型红巨星，在宽带滤波器V和I的基础上增加了中带滤波器[79]和[81]。从这些图像中得到的彩色星等图显示了两个序列，它们可能对应于英仙座臂和银河系外缘。较低序列的明显清晰的轮廓表明了恒星密度分布的急剧下降。在每个色图的碳星星分支上发现了几颗恒星。另一方面，M型巨星分支上的恒星数量很少。用Nobeyama 45米射电望远镜观测了近100个IRAS源的SiO脉泽辐射。检测率出奇地低，部分原因是富碳源的污染。他们还用木曾施密特望远镜反复观察，以确定其光变化的周期。木曾天文台刚刚开始研制大幅面CCD照相机。利用这种新的CCD相机进行巡天观测，将在今后的银河系结构研究中发挥重要作用。

Red giants exhibit a range of properties which make them particularly useful to study a distant region of our galaxy. They are intrinsically bright, making it possible to detect and work on them at a distance of several kpc. They are abundant enough to search for the global structure of the galaxy.A CCD camera installed onto the Kiso Schmidt Telescope was used to take images towards the anti-Galactic center. The medium band filters [79] and [81] were added to wide band filters V and I in order to discriminate carbon stars from M-type red giants.Color magnitude diagrams obtained from these images showed two sequences which probably correspond to the Perseus arm and the outer edge of our Galaxy. Rather steep decline of the stellar density distribution was indicated from the apparently clear delineation of the lower sequence. Several stars were found on the carbon star branch of each color-color diagram. On the other hand, few stars were located on the M-type giant branch. The confirmation of this marked contrast is a subject of the future study.Nearly one hundred IRAS sources were observed for the SiO maser emission with the Nobeyama 45m radio telescope. The detection rate was surprisingly low, partly due to the contamination by the carbon rich sources. They were also observed with the Kiso Schmidt telescope repeatedly to determine the period of their light variation. Development of the large format CCD camera was just started at Kiso Observatory. Survey observations using this new CCD camera will flourish in the futere study of the Galactic structure.