Advertisement

Solar Physics

, 294:77 | Cite as

Christian Horrebow’s Sunspot Observations – I. Life and Published Writings

  • Carsten Sønderskov Jørgensen
  • Christoffer KaroffEmail author
  • V. Senthamizh Pavai
  • Rainer Arlt
Article

Abstract

Between 1761 and 1776, Christian Horrebow made regular observations of sunspots from Rundetårn in Copenhagen. Based on these observations he writes in 1775 that “it appears that after the course of a certain number of years, the appearance of the Sun repeats itself with respect to the number and size of the spots”. Thus, Horrebow hypothesized the idea of a cyclic Sun several decades before Heinrich Schwabe discovered the solar cycle and estimated its period. This proves the ability of Horrebow as a sunspot observer. In this article, we present a general overview of the work of Christian Horrebow, including a brief biography and a complete bibliography. We also present a translation from Danish to English of his writings on sunspots in the Dansk Historisk Almanak. These writings include tables of daily sunspot measurements of which we discuss the completeness.

Keywords

Solar cycle, observations Sunspots 

Notes

Acknowledgements

We would like to thank the referee for thoughtful comments which significantly improved the paper. The translation of Christian Horrebow’s published papers on sunspots was done by Lenore Messick, Events and Communication Support, Aarhus University. The project has been supported by the Villum Foundation. Funding for the Stellar Astrophysics Centre is provided by the Danish National Research Foundation (grant agreement no. DNRF106), funding for VSP is provided by the Deutsche Forschungsgemeinschaft (grant no. AR355/12-1). We are very grateful to Susanne Elisabeth Nørskov, who has been most helpful throughout the project with finding the notebooks and other historical texts. We are also grateful to Kristian Hvidtfelt Nielsen, who helped with interpreting the historical texts.

Disclosure of Potential Conflicts of Interest

The authors declare that they have no conflicts of interest.

Supplementary material

11207_2019_1465_MOESM1_ESM.pdf (2.5 mb)
(PDF 2.5 MB)
11207_2019_1465_MOESM2_ESM.pdf (66 kb)
(PDF 66 kB)
11207_2019_1465_MOESM3_ESM.pdf (5.7 mb)
(PDF 5.7 MB)
11207_2019_1465_MOESM4_ESM.pdf (2.2 mb)
(PDF 2.2 MB)
11207_2019_1465_MOESM5_ESM.pdf (1.3 mb)
(PDF 1.3 MB)
11207_2019_1465_MOESM6_ESM.pdf (1.1 mb)
(PDF 1.1 MB)
11207_2019_1465_MOESM7_ESM.pdf (689 kb)
(PDF 689 kB)
11207_2019_1465_MOESM8_ESM.pdf (978 kb)
(PDF 978 kB)
11207_2019_1465_MOESM9_ESM.pdf (907 kb)
(PDF 907 kB)
11207_2019_1465_MOESM10_ESM.pdf (1.1 mb)
(PDF 1.1 MB)

References

  1. Arlt, R.: 2008, Digitization of sunspot drawings by Staudacher in 1749 – 1796. Solar Phys. 247, 399. DOI. ADS. CrossRefGoogle Scholar
  2. Bugge, T.: 1784, Observationes Astronomicae Annis 1781, 1782 and 1783. ADS. Google Scholar
  3. Clette, F., Svalgaard, L., Vaquero, J.M., Cliver, E.W.: 2014, Revisiting the sunspot number. A 400-year perspective on the solar cycle. Space Sci. Rev. 186, 35. DOI. ADS. CrossRefGoogle Scholar
  4. Gyldenkerne, K., Darnell, P.B.: 1990, Dansk astronomi gennem firehundrede år. Google Scholar
  5. Horrebow, P.: 1735, Basis astronomiae sive astronomiae pars mechanica in qua Danica; simulque eorundem usus, sive methodi observandi Roemerianae describuntur observatoria, atque instrumenta astronomica Roemeriana. DOI. ADS. CrossRefGoogle Scholar
  6. Hoyt, D.V., Schatten, K.H.: 1995, A new interpretation of Christian Horrebow’s sunspot observations from 1761 to 1777. Solar Phys. 160, 387. DOI. ADS. CrossRefGoogle Scholar
  7. Hoyt, D.V., Schatten, K.H.: 1998, Group sunspot numbers: a new solar activity reconstruction. Solar Phys. 181, 491. DOI. ADS. CrossRefGoogle Scholar
  8. Karoff, C., Jørgensen, C.S., Senthamizh Pavai, V., Rainer, A.: 2019, Christian Horrebow’s sunspot observations – II. Construction of a record of sunspot positions. Solar Phys. DOI.
  9. Muñoz-Jaramillo, A., Vaquero, J.M.: 2019, Visualization of the challenges and limitations of the long-term sunspot number record. Nat. Astron. 3, 205. DOI. ADS. CrossRefGoogle Scholar
  10. Schwabe, H.: 1844, Sonnenbeobachtungen im Jahre 1843. Von Herrn Hofrath Schwabe in Dessau. Astron. Nachr. 21, 233. DOI. ADS. CrossRefGoogle Scholar
  11. Svalgaard, L.: 2017, A recount of sunspot groups on Staudach’s drawings. Solar Phys. 292, 4. DOI. ADS. CrossRefGoogle Scholar
  12. Svalgaard, L., Schatten, K.H.: 2016, Reconstruction of the sunspot group number: the Backbone method. Solar Phys. 291, 2653. DOI. ADS. CrossRefGoogle Scholar
  13. Thiele, T.N.: 1859, De Macularum Solis antiquioribus quibusdam obstervationibus Hafniae institutis, scripsit Th. N. Thiele, astr. stud. Astron. Nachr. 50, 257. DOI. ADS. CrossRefGoogle Scholar
  14. Usoskin, I.G., Kovaltsov, G.A., Lockwood, M., Mursula, K., Owens, M., Solanki, S.K.: 2016, A new calibrated sunspot group series since 1749: statistics of active day fractions. Solar Phys. 291, 2685. DOI. ADS. CrossRefGoogle Scholar
  15. Vaquero, J.M., Svalgaard, L., Carrasco, V.M.S., Clette, F., Lefèvre, L., Gallego, M.C., Arlt, R., Aparicio, A.J.P., Richard, J.-G., Howe, R.: 2016, A revised collection of sunspot group numbers. Solar Phys. 291, 3061. DOI. ADS. CrossRefGoogle Scholar
  16. Wolf, R.: 1873, Astronomische Mittheilungen XXIII. Astron. Mitt. Eidgenöss. Sternwarte Zür. 4, 77. ADS. Google Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Stellar Astrophysics Centre, Department of Physics and AstronomyAarhus UniversityAarhus CDenmark
  2. 2.Department of GeoscienceAarhus UniversityAarhus CDenmark
  3. 3.Leibniz-Institut für Astrophysik PotsdamPotsdamGermany

Personalised recommendations