Tenmongata

The Tenmongata (天文方, Astronomy Agency) was an institute for astronomical studies operated by the Tokugawa shogunate in Edo, Japan (today's Tokyo).

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 in the 7th century.

[1] The institute was also responsible for surveying, chorography, and translating European academic books and papers.

[2] 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.