The Development of Astronomy and Emergence of Astrophysics in Japan

Abstract

This chapter overviews the emergence and development phases of modern astronomy and astrophysics in Japan, mainly before WWII. In the beginning of the nineteenth century under the samurai regime of the Tokugawa Shogunate, shogunal astronomers started to learn Western astronomy through a Dutch translation of the book Astronomie by J.J. Lalande. After the Meiji Restoration (1868) the new government founded the University of Tokyo (1877), the first modern university in Japan, in which Tokyo Astronomical Observatory (TAO) also started in 1888. Terao Hisashi, who had gone to Paris to study the modern astronomy, became the first Director of TAO in 1888. The astronomy introduced by Terao into Japan was so-called classical astronomy. Two of Terao’s early students made Japan’s first internationally recognized achievements in astronomy, the discovery of the Z-term in the polar motion of the Earth by Kimura (Astronomische Nachrichten, 158, 234–240, 1902) and the discovery of asteroid families by Hirayama (Astronomical Journal, 31, 185–188, 1918).