Sunspot latitudes during the Maunder Minimum: A machine-readable catalogue from previous studies
Introduction
The Maunder Minimum (hereafter, MM) is a special episode of the Sun history (Eddy, 1976) when sunspots almost completely vanished, while the solar wind kept blowing, although at a reduced pace (Cliver et al., 1998, Usoskin et al., 2001). Sunspots rarely appeared but an analysis of 10Be data (Beer et al., 1998) implies that the 11-year cycle was weak but fairly regular during the MM. Reviews about the MM and the historical aspect of solar activity can be found in Soon and Yaskell, 2003, Vaquero, 2007, Vaquero and Vázquez, 2009, Usoskin, 2013. Although the classical scenario implies that the transition from the normal high activity to the deep minimum did not have any apparent precursor, newly recovered historical observations suggest that the onset of the MM could not have been very sudden (Vaquero et al., 2011). Other important feature of sunspot activity during the MM was a strong north–south (hereafter, N–S) asymmetry. Sunspots were mainly observed in the southern solar hemisphere (Spörer, 1889, Ribes and Nesme-Ribes, 1993).
Two important studies have clearly shown this last feature of the MM. On the one hand, Spörer (1889) indicated, in a pioneering paper published in the 19th century, this strong asymmetry, listing the known sunspot positions, based mainly on published observations and drawings. Furthermore, Ribes and Nesme-Ribes (1993) reported the characteristics of solar activity during the MM from observations preserved in the archives of the Paris Observatory. Moreover, they published a butterfly diagram for the 1670–1720 period based on these observations. These two studies are the main source of sunspot latitudes during the MM except the original observations (Clette et al., 2014, Casas et al., 2006).
Although several butterfly diagrams have been made in recent years with data from 18th (Arlt, 2009, Cristo et al., 2011) and 19th (Arlt et al., 2013, Casas and Vaquero, 2014) centuries, no data are available (in a machine-readable version) to build a butterfly diagram for the 17th century (especially for MM). In regard to this, the aim of this paper is to provide the international scientific community a machine-readable version of sunspot latitudes from the works of Spörer (1889) and Ribes and Nesme-Ribes (1993).
Section snippets
Data and method
As we have pointed out in the preceding section, we have recovered data from the works of Spörer (1889) and Ribes and Nesme-Ribes (1993). The origin of the data is quite different. Spörer (1889) provided only a list of sunspot latitudes. However, Ribes and Nesme-Ribes (1993) consulted the original data in the archive of the Paris Observatory and published a butterfly diagram (upper panel of Fig. 6 in Ribes and Nesme-Ribes, 1993). Therefore, we have built a database extracting the information of
Results
We have merged both datasets into a single file containing three columns. The first column indicates the date associated to the sunspot latitude, that is listed in the second column. We have used the criterion of assigning the date of each sunspot to the midpoint between the extreme observation dates indicated by Spörer (1889). The last column shows the source. Fig. 1 shows the sunspot latitudes from Spörer (red circles) and Ribes and Nesme-Ribes (blue squares).
Since the purpose of this work is
Asymmetry through the MM
Both data sets show clearly the strong N–S asymmetry during the MM with sunspots mainly observed in the southern solar hemisphere. In the first solar cycle after the MM in the 1710s this asymmetry vanished. For studying the N–S asymmetry in each decade, we have calculated the asymmetry index A, defined as (Verma, 1993)SN and SS being, respectively, the number of spots observed in the northern and southern hemispheres. Table 1 displays the values of SN and SS, SN + SS and the index A
Conclusion
We have recovered two data sets of sunspot latitudes during the MM for the international scientific community. The first data set is based in Spörer (1889) and the second data set is based on the sunspot latitudes displayed in the butterfly diagram for the MM which was published by Ribes and Nesme-Ribes (1993). We used the web tool WebPlotDigitizer to extract the data from the figure of the butterfly diagram published by Ribes and Nesme-Ribes (1993). Thus, a machine-readable version of these
Acknowledgments
Support from the Junta de Extremadura (Research Group Grants GR10131 and GR10045), Ministerio de Economía y Competitividad of the Spanish Government (AYA2011-25945) and the COST Action ES1005 TOSCA (http://www.tosca-cost.eu) is gratefully acknowledged.
References (22)
- et al.
Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables
(1972) The solar butterfly diagram in the 18th century
Solar Phys.
(2009)- et al.
Sunspot positions and sizes for 1825–1867 from the observations by Samuel Heinrich Schwabe
Mon. Not. R. Astron. Soc.
(2013) - et al.
An active sun throughout the maunder minimum
Solar Phys.
(1998) - et al.
Solar rotation in the 17th century
Solar Phys.
(2006) - et al.
The sunspot catalogues of Carrington, Peters, and de la Rue: quality control and machine-readable versions
Solar Phys.
(2014) - Chowdhury, P., Dwivedi, B.N., 2011. A study of the north–south asymmetry of sunspot area during solar cycle 23. In:...
- et al.
Revisiting the Sunspot Number. A 400-year perspective on the solar cycle
Space Sci. Rev.
(2014) - et al.
Geomagnetic activity and the solar wind during the Maunder Minimum
Geophys. Res. Lett.
(1998) - et al.
HSUNSPOTS: a tool for the analysis of historical sunspot drawings
J. Atmos. Solar-Terr. Phys.
(2011)
The Maunder minimum
Science
Cited by (34)
Temporal variation and asymmetry of sunspot and solar plage types from 1930 to 1936
2019, Advances in Space ResearchCitation Excerpt :Spoerer (1889) and Maunder (1890) noted that there was a period of time associated to a very low solar activity when most of the sunspots appeared more frequently in the southern hemisphere. More recent studies have confirmed this strong asymmetry during the so-called Maunder minimum (Usoskin et al., 2015; Vaquero et al., 2015). Newton and Milson (1955) studied this asymmetry in the yearly values of sunspot and plage areas during 7 sunspots cycles, from 1874 to 1954.
A small collection of sunspot drawings made in the Royal Astronomical Observatory of the Spanish Navy in 1884
2016, Advances in Space ResearchCitation Excerpt :Recently, Diercke et al. (2015) have digitized the sunspot drawings made by G. Spörer from 1861 to 1894. All these contributions, together with the historical sunspot catalogues, can help to increase our knowledge of solar activity in the historical period (Casas and Vaquero, 2014; Vaquero et al., 2015; Lefevre and Clette, 2014). The Royal Astronomical Observatory of the Spanish Navy located in San Fernando, Cádiz, was founded in 1753.
Sunspot drawings handwritten character recognition method based on deep learning
2016, New AstronomyCitation Excerpt :Accurate and almost continuous record of the sunspots are determined from digitized sunspot drawings(Arlt, 2009; 2011; Arlt and Frohlich, 2012). Reliable sunspot catalogues in historical times including the 17th century, obtained from sunspot drawings, can be provided to the scientific community (Carrasco et al., 2014; Casas and Vaquero, 2014; Vaquero et al., 2015). Lefevre and Clette merge the information from parallel catalogs to form a better central database that collects a much more comprehensive record of sunspots and sunspot groups (Lefevre and Clette, 2014).
Sunspot and Group Number: Recent advances from historical data
2018, Proceedings of the International Astronomical UnionSunspot Observations at the Eimmart Observatory: Revision and Supplement
2023, Solar PhysicsSunspot Observations at the Eimmart Observatory: Revision and Supplement
2023, Research Square