Historical sunspot observations: A review

By J. Vaquero. 2007

182 citations recorded by the source corpus.

Abstract Early observations of sunspots were made by the naked eye. We discuss here the possibilities to use these records to study the long-term change in the Sun. Other historical sunspot observations with camera obscura are also discussed. The best record of the behaviour of the Sun is available for the last four centuries thanks to the observations of sunspots with telescope. These observations allow us to know the number, position, and area of sunspots as well as some specific episodes like the Maunder Minimum, optical flares, etc. Rudolf Wolf developed the first reconstruction of solar activity in the 19th century. Another reconstruction was made by Hoyt and Schatten in 1998 which improves the database and uses a new methodological approach. Here we also discuss some mistakes, pending tasks and minor improvements related to sunspot observations.

Subfields: Astronomy and Astrophysics, Oceanography

View Paper: https://www.semanticscholar.org/paper/37002f5ea839f493eb686857f3e428d504b94af5

How researchers see this paper

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In Astronomy and Astrophysics

1. I. Usoskin
2. S. Solanki
3. G. Kovaltsov
4. M. Lockwood
5. N. Krivova
6. F. Clette
7. L. Svalgaard
8. K. Mursula

In Oceanography

1. I. Usoskin
2. M. Lockwood
3. N. Krivova
4. S. Solanki
5. G. Kovaltsov
6. F. Clette
7. L. Svalgaard
8. E. Cliver

Citations in the corpus

• Revisiting the Sunspot Number (2014, background): “hat there is no data for the year 1637 in the original GN series. 2. The estimated (not observed) values from Crabtree's comments (16381639) were - eliminated. This problem has been discussed in Vaquero (2007). 3. The dates and numbers of sunspot groups from Horrox observations in Hoyt and Scha”
• The Maunder minimum (1645–1715) was indeed a grand minimum: A reassessment of multiple datasets (2015, background): “This series, however, contains a large number of generic no-spot statements (i.e. that no spots were seen on the Sun during long periods), which should be treated with caution (Kovaltsov et al. 2004; Vaquero 2007; Clette et al. 2014; Zolotova & Ponyavin 2015; Vaquero et al. 2015a, see also Sect.”
• A History of Solar Activity over Millennia (2008, unknown): “For example, about 300 pages of logs of solar observations made in the cathedral of San Petronio in Bologna from 1655 – 1736 were published by Eustachio Manfredi in 1736 (see the full story in Vaquero, 2007).”
• From the Wolf number to the International Sunspot Index: 25 years of SIDC (2007, background): “The historical era is entirely based on reconstruction from sparse data and is still a topic of research (e.g. Letfus, 2000; Usoskin et al., 2003; Vaquero, 2007).”
• A Revised Collection of Sunspot Group Numbers (2016, background): “They are listed in Table 3 of Vaquero (2007).”