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Recent studies of radioisotopes in tree rings or ice cores suggest that extreme space weather events occurred in the pre-telescope age. Observational records of naked-eye sunspots and low-latitude auroras in historical Chinese documents in pretelescopic age in the period of Suí, Táng, the Five Dynasties and Ten Kingdoms during 581-960 Common Era can provide useful information on past solar activity. These official histories contain records of continuous observations with well-formatted reports conducted under the policy of the government. (Source: Leif): https://tinyurl.com/k7t67wa
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