A modern reconstruction of Carrington's observations (1853-1861)

TL;DR

This paper re-analyzes Richard Carrington's historic sunspot observations to update the Sunspot Number series, comparing his counting methods with modern techniques and validating the new data's robustness.

Contribution

It provides a modern recount of Carrington's original sunspot observations, enabling improved integration into current Sunspot Number series and analysis.

Findings

Carrington's group counting aligns closely with modern methods

His individual spot counting lags behind modern counts

The new recount is robust and comparable to contemporary data

Abstract

The focus of this article is a re-count of Richard Carrington's original sunspot observations from his book drawings (Carrington,1863) by an observer from the World data Center-SILSO network, Thomas H. Teague(UK). This modern recount will enable the use of Carrington's observations in the re-computation of the entire Sunspot Number series in a way Carrington's original counts (Casas and Vaquero,2014) did not. here we present comparison studies of the new recounted series with contemporary observations, new data extracted from the Journals of the Zurich Observatory and other sources of Carrington's own observations and conclude that Carrington's group counting is very close to the modern way of counting while his method for counting individual spots lags significantly behind modern counts. We also test the quality and robustness of the new re-count with methods developed in Mathieu et al.,2019.