Hisako Koyama

Hisako Koyama (1916–1997) Koyama worked as a staff member of the National Museum of Nature and Science, Tokyo for more than 40 years and completed more than 10,000 solar sketches during her lifetime. In 1986, she was the recipient of the Oriental Astronomical Association Prize of Encouragement of Academic Research. In 2012, a minor planet was renamed 3383 Koyama in honour of her at the proposal of another Oriental Astronomical Association member.

Early life Growing up, Koyama developed an interest in astronomy and making space observations. Before she began her career as a staff observer, Koyama would read books about astronomy and go star watching with astronomical charts. During World War II, she would use city-wide air-raid blackouts as opportunities to set up a futon in her yard and make celestial observations.

Legacy

In 2014, an international team of researchers utilized Koyama’s sunspot records to reconstruct a nearly 400-year history of sunspot activity, dating from the 1610s and the early 2000s. The project also relied on sketches drawn by Galileo Galilei, Pierre Gassendi, Johann Caspar Staudacher, Heinrich Schwabe, and Rudolf Wolf. Because Koyama’s sketches were created using the same 20 cm refractor telescope and the same observation method, the researchers were able to use her observations as a backbone for calibrating parts of the sunspot record.

Selected publications

Koyama, H. (1985). Observations of Sunspots 1947–1984. Tokyo: Kawade Shobo Shinsha Publishers. Koyama, H. (1981). 35 years with the 20 cm telescope [in Japanese]. Natural Science and Museums, 48(3), 111–116