Solar Rotation in the Period 1611 – 1631 Determined Using Observations of Christoph Scheiner

Recently Arlt et al. ( Astron. Astrophys . 595 , A104, 2016 ) published archival sunspot data measured by Cristoph Scheiner in the period from 1611 to 1631. Scheiner’s data precede Maunder minimum. The main goal of this paper is to study several aspects of sunspot motion across the solar disk (rotation, meridional motion, Reynolds stress) to investigate possible clues about the grand solar minimum that started soon after these observations were made. Another objective is to estimate quality and usefulness of the archival sunspot data for scientific analysis in present times. We used the daily shift method to calculate velocities from positional and temporal data of sunspots measured by Scheiner. Considering the errors of the calculated parameters, solar rotation profile and meridional motions are the same as the modern data show. Correlation and covariance of the solar rotation residual and meridional velocities are different than observed today by tracing sunspot motion. Correlation and covariance of the solar rotation residual and meridional velocities show some signs that might indicate changes in the solar dynamo mechanism before the Maunder minimum. Archival sunspot data, in this case, are of good quality for scientific analysis and provide a valuable resource for modern scientific research.