The Tenmongata (天文方, Astronomy Agency) was an institute for astronomical studies operated by the

Tokugawa shogunate The Tokugawa shogunate, also known as the was the military government of Japan during the Edo period from 1603 to 1868. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil wars ...

Edo Edo (), also romanized as Jedo, Yedo or Yeddo, is the former name of Tokyo. Edo, formerly a (castle town) centered on Edo Castle located in Musashi Province, became the '' de facto'' capital of Japan from 1603 as the seat of the Tokugawa shogu ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

(today's

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

). It is one of the predecessors of today's

University of Tokyo The University of Tokyo (, abbreviated as in Japanese and UTokyo in English) is a public research university in Bunkyō, Tokyo, Japan. Founded in 1877 as the nation's first modern university by the merger of several pre-westernisation era ins ...

Overview

Traditionally, astronomical studies and revision of the calendar were carried out by the Onmyo-no-tsukasa (陰陽寮), which was established by

Emperor Tenmu was the 40th Emperor of Japan,Imperial Household Agency (''Kunaichō'') 天武天皇 (40) retrieved 2013-8-22. according to the traditional order of succession. Ponsonby-Fane, Richard. (1959). ''The Imperial House of Japan'', p. 53. He ascended ...

in the 7th century. The institute was established in 1684 when the Tokugawa Shogunate decided to switch from the Senmyō calendar, which had been in use for 823 years and had thus accumulated significant errors, to the newly invented

Jōkyō calendar The was a Japanese lunisolar calendar, in use from 1684 to 1753.Nussbaum"''Jōkyō-reki''"at p. 431"''Teikyō-reki''"at p. 431 It was officially adopted in 1685.Orchiston, Wayne ''et al.'' (2011)''Highlighting the History of Astronomy in the Asi ...

. The inventor of the calendar, Harumi Shibukawa, was appointed as the head of the institute. The institute was also responsible for surveying, chorography, and translating European academic books and papers. The translation department (蛮書和解御用, Bansho Wagegoyo) eventually spun off to form the

Bansho Shirabesho The ', or "Institute for the Study of Barbarian Books," was the Japanese institute charged with the translation and study of foreign books and publications in the late Edo Period. Origin The institute was founded in 1856 that catered to the s ...

, one of the predecessors of humanities studies at the

. The eighth shogun Yoshimune invested heavily in this institute to absorb European modern natural science, resulting in an accumulation of distinguished scholars, imported materials and equipments. The Kansei Calendar was developed by Yoshitoki Takahashi in 1798, which took into account the elliptical orbits of the sun and moon. His student Tadataka Ino and he completed the first comprehensive modern map of Japan in 1821. The office of chief astronomer was officially hereditary, but often, outstanding astronomers were adopted, making it meritocratic in practice. After the

Meiji Restoration The , referred to at the time as the , and also known as the Meiji Renovation, Revolution, Regeneration, Reform, or Renewal, was a political event that restored Imperial House of Japan, imperial rule to Japan in 1868 under Emperor Meiji. Althoug ...

, it became one of the direct predecessors of sciences studies at the University of Tokyo.

References

{{University of Tokyo Science and technology during the Edo period