Forty two years counting spots: solar observations by D. E. Hadden during 1890-1931 revisited
arXiv:1305.6661 · doi:10.1016/j.newast.2013.05.002
Abstract
We have recovered the sunspot observations made by David E. Hadden during 1890-1931 from Alta, Iowa. We have digitized the available data published by Hadden in different astronomical journals. This data series have been analyzed and compared with the standard sunspot number series. Moreover, we provide additional information on two great sunspot groups, previously not described, that originated two important extreme episodes of space weather on February 1892 and September 1898.
19 pages, 9 figures, to be published in "New Astronomy"
References in corpus (1)
Cited by in corpus (8)
- A Revised Collection of Sunspot Group Numbers
- New reconstruction of the sunspot group number since 1739 using the direct calibration and "backbone" methods
- Sunspot Numbers and Areas from the Madrid Astronomical Observatory (1876-1986)
- Updated sunspot group number reconstruction for 1749-1996 using the active day fraction method
- Sunspot Catalogue of the Valencia Observatory (1920-1928)
- Dependence of the Sunspot-group Size on the Level of Solar Activity and its Influence on the Calibration of Solar Observers
- Eric Strach: four decades of detailed synoptic solar observations (1969-2008)
- A Transit of Venus Possibly Misinterpreted as an Unaided-Eye Sunspot Observation in China on 9 December 1874