First solar butterfly diagram from Schwabe's observations in 1825-1867
arXiv:1010.3131 · doi:10.1017/S1743921311015390
Abstract
The original sunspot observations by Heinrich Samuel Schwabe of 1825-1867 were digitized and a first subset of spots was measured. In this initial project, we determined more than 14 000 sunspot positions and areas comprising about 11% of the total amount of spots available from that period. The resulting butterfly diagram has a typical appearance, but with evident north-south asymmetries.
3 pages, 1 figure, Proceedings of IAU symposium 273, Physics of Sun and star spots, Ventura, California 22-26 August 2010