[M-IS22] History X Earth and Planetary Science

[MIS22-09] Understanding the actual state of observations by the Tsuchimikado family by comparing comet records

*Harufumi Tamazawa^1,2, kiyomi iwahashi³, Reizaburo Kitai⁴ (1.Kyoto City University of Arts, 2.Kyoto University, 3.Kokugakuin University, 4.Ritsumeikan University)

Keywords:History of Astronomy, Comet

During the Edo period, astronomical observations were continuously conducted by the Tsuchimikado family in Kyoto and the Tenmonkata of the Shogunate in Edo. Although there are differences in observation accuracy depending on the period, it is useful to compare independent observation records in Japan and other countries in order to grasp the actual situation. Comet Donati, which appeared in 1858, was observed in Japan by the Tsuchimikado family in Kyoto, the Observatory of the Edo Shogunate, and the Osakama family, and their observation records are preserved. Records are also kept in Europe, and the altitude and direction are recorded as numerical values. From these observation records, we derived the daily right ascension and declination values of the comet and compared the observational accuracy. Although it fell, it was found that the entire orbit could be roughly grasped, and that the observation of the Tsuchimikado family was the best in Japan at that time (Iwahashi, Kitai, Tamazawa 2022). A similar comparison can be made, for example, to the Tsuchimikado family and to the Klinker-Hughes comet of 6th year of Kaei. In this presentation, I will explore the actual state of observations by the Tsuchimikado family at the time, using the Donati-Klinker-Hughes comets as clues.