Hisako Koyama Drew Sunspots Daily

Japanese solar observer Hisako Koyama began submitting sunspot sketches in 1944 and started professional work at Tokyo’s National Museum of Nature and Science in 1946. From 1947 to 1984, she hand drew sunspots almost every day, documenting more than 8,000 sunspot groups and later publishing the record in “Observations of Sunspots.” Her long, consistent timeline helped researchers rebuild centuries of solar activity and study solar cycles and the Sun’s magnetic fields.

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