A total of 70 members in the institute, including faculty members, postdoctoral researchers, and students, are working over wide variety of problems related to astronomical objects. The research activities cover 1) searching for planets around nearby stars, 2) understanding of physical properties of stars in our Galaxy, 3) revealing formation and evolution processes of galaxies in the distant universe, and 4) understanding cosmological framework of the universe. These subjects are studied in two ways. The first is through theoretical research, where models are created and analyzed to understand a variety of fundamental astronomical phenomena on the basis of physics and mathematics, occasionally using computational resources such as super-computers. The second is through observational research. Astronomical phenomena are observed with electromagnetic waves at all wavelengths, i.e., radio, infrared, optical, ultraviolet, X-ray and gamma-rays using various modern telescopes, such as the 8.2m Subaru Telescope at the summit of 4,200-m Mauna Kea on the island of Hawaii. The data obtained with such observations are analyzed and compared with physical models of the astronomical phenomena. Opening up a new window to unexplored universe by developing a new telescope and cutting-edge instruments is also unique and important activity in the institute.