Oct 27 – 31, 2025
Europe/Stockholm timezone

Reconstruction of sunspot parameters from observations by Philippe de La Hire in 1676-1702

Oct 27, 2025, 4:15 PM
15m
Miklagård

Miklagård

Oral CD3 - Refining the Sunspot Number Series : challenges and benefits for the Space Climate Community CD3 - Refining the Sunspot Number Series : challenges and benefits for the Space Climate Community

Speaker

Mikhail Vokhmyanin (University of Oulu)

Description

Parisian solar observations constitute the richest sunspot data set covering the Maunder minimum. Thirty years ago, sunspot latitudes were reconstructed by Elisabeth Nesme-Ribes, but these data have been lost. We present an extensive set of newly reconstructed sunspot parameters for both sunspot groups and individual sunspots. Based on the hand-written notes in the observational journals by Philippe de La Hire we carefully evaluated areas (both umbra and penumbra), latitudes, longitudes, as well as other parameters. We also estimated the differential rotation, and the fraction of sunspot groups obeying or violating Joy's law.

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Primary author

Nadezhda Zolotova (St. Petersburg State University)

Co-author

Mikhail Vokhmyanin (University of Oulu)

Presentation materials