A Sunspot Catalog for the Period 1952-1986 from Observations Made at the Madrid Astronomical Observatory

TL;DR

This paper presents a recovered sunspot catalog from Madrid Observatory covering 1952-1986, including metadata and validation against other datasets, aiding solar activity research.

Contribution

It provides a newly recovered, machine-readable sunspot catalog for 1952-1986 with metadata and reliability analysis, enhancing historical solar activity data.

Findings

Catalog covers over three solar cycles.

Machine-readable format available for research.

Validated dataset against other sunspot catalogs.

Abstract

Sunspot catalogs are very useful for studying the solar activity of the recent past. In this context, a catalog covering more than three solar cycles made by the astronomers of the Madrid Astronomical Observatory in Spain (nowadays, the National Astronomical Observatory) from 1952 until 1986 has been recovered. Moreover, a machine-readable version of this catalog has been made available. We have recovered abundant metadata and studied the reliability of this dataset by comparing it with other sunspot catalogs.