The Book of Han's Treatise on the Five Phases states: "In the third month of the first year of Heping, the sun rose yellow, with black vapor the size of a coin in the center of the sun." It is the world's earliest recognized definite sunspot record. From Han to Qing, official histories preserved over 100 sunspot records, and modern researchers have used them to reconstruct a 2,000-year solar activity curve and study the Maunder Minimum and its relationship to climate.
Account
The Book of Han's Treatise on the Five Phases states: "In the third month of the first year of Heping, the sun rose yellow, with black vapor the size of a coin in the center of the sun." It is the world's earliest recognized definite sunspot record. From Han to Qing, official histories preserved over 100 sunspot records, and modern researchers have used them to reconstruct a 2,000-year solar activity curve and study the Maunder Minimum and its relationship to climate.
Sources
- Book of Han, "Treatise on the Five Phases"
- astronomical treatises of successive dynasties
- modern solar activity cycle reconstruction studies