Solar Rotation Determined from Thomas Harriot's Sunspot Observations of 1611 to 1613

  title={Solar Rotation Determined from Thomas Harriot's Sunspot Observations of 1611 to 1613},
  author={R. Herr},
  pages={1079 - 1081}
  • R. Herr
  • Published 1978
  • Physics, Medicine
  • Science
In 1612 the sun's mean sidereal rotation rate was only 13.3� per day based on a series of 199 unpublished drawings by Harriot. By comparison with the rates in 1625 to 1626 and 1642 to 1644 it appears that the solar rotation was accelerating significantly in the cycles leading up to the Maunder minimum. 

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Harriot's original sunspot drawings are the posSCIENCE
  • Library of the University of Delaware. I worked from the Delaware copy ofHMC 241/8,
  • 1978
Observations on the Spots on the Sun from November 9, 1853 to March 24, 1861, Made at Redhill (Williams and Norgate, London, 1863)
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  • 1974
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  • Baron de Zach remarks on the assertion that Thomas Harriot
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