Survey of the Outer Galaxy

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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.