Systematic sunspot records
Registro sistemático de manchas solares
- Date
- 28 BCE · confidence high
- Place
- Chang'an (Xi'an), Shaanxi, China
- Credited to
- Han court astronomers (Hanshu)
- Field
- Cosmos & Earth
What was discovered
The Hanshu records a dark spot on the Sun in 28 BCE, the start of an official series of more than a hundred observations up to the Ming period. They are useful data for reconstructing historical solar activity.
There are earlier, imprecise mentions; in Europe sunspots have been studied telescopically since 1610-1611.
What it led to
- historical series for studying the solar cycle