✦ LIBER ✦

Solar rotation velocity as determined from sunspot drawings of J. Hevelius in the 17th century

✍ Scribed by Claudia Abarbanell; Hubertus Wöhl

Publisher: Springer
Year: 1981
Tongue: English
Weight: 291 KB
Volume: 70
Category: Article
ISSN: 0038-0938
DOI: 10.1007/bf00154400

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✦ Synopsis

Using two original copies of Hevelius' 'Selenographia' and reducing spot positions with two different methods, we found that the solar angular rotation velocity at the beginning of the Maunder minimum was about the same as today. The gradient of the differential rotation was slightly steeper than given in modern reductions, but not significantly different. These findings are in contradiction to those published by Eddy et al. (1976).