Sunspot latitudes during the Maunder Minimum: a machine-readable catalogue from previous studies

TL;DR

This paper provides a machine-readable catalogue of sunspot latitudes during the Maunder Minimum, confirming hemispherical asymmetry and making historical data accessible for further solar activity research.

Contribution

It recovers and digitizes two historical sunspot latitude data sets for the Maunder Minimum, enabling easier access and analysis for the scientific community.

Findings

Confirmed strong hemispherical asymmetry during the Maunder Minimum.

Provided a machine-readable catalogue of historical sunspot data.

Validated historical sunspot distributions with modern data formats.

Abstract

The Maunder Minimum (1645-1715 approximately) was a period of very low solar activity and a strong hemispheric asymmetry, with most of sunspots in the southern hemisphere. In this paper, two data sets of sunspot latitudes during the Maunder minimum have been recovered for the international scientific community. The first data set is constituted by latitudes of sunspots appearing in the catalogue published by Gustav Sp\"orer nearly 130 years ago. The second data set is based on the sunspot latitudes displayed in the butterfly diagram for the Maunder Minimum which was published by Ribes and Nesme-Ribes almost 20 years ago. We have calculated the asymmetry index using these data sets confirming a strong hemispherical asymmetry in this period. A machine-readable version of this catalogue with both data sets is available in the Historical Archive of Sunspot Observations (http://haso.unex.es) and in the appendix of this article.