First solar butterfly diagram from Schwabe's observations in 1825-1867

TL;DR

This study digitized Heinrich Schwabe's 1825-1867 sunspot observations, measured over 14,000 spots, and produced the first butterfly diagram from this historical data, revealing typical patterns and asymmetries.

Contribution

First digital analysis and butterfly diagram creation from Schwabe's original sunspot observations covering 1825-1867.

Findings

Produced a butterfly diagram showing sunspot distribution.

Identified north-south asymmetries in sunspot activity.

Measured over 14,000 sunspots from historical data.

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.