hide
Free keywords:
-
Abstract:
Quantifications of solar magnetic activity have been key references for the long-term variability of the solar-terrestrial environments, space-weather impacts on the Earth, and research of other (especially Sun-like) stars. So far, astronomers have observed the Sun and recorded/counted sunspots and sunspot groups from 1610 onward. Their records have formed not only a basis for reconstructions of solar magnetic activity in terms of sunspot (group) numbers and sunspot positions but also one of the longest-running scientific experiments in human history. However, their source records have occasionally remained unpublished in historical archives and have not been immediately accessible to the scientific community. This presentation briefly shows some cases of different source accessibility, their collection process, applications, and accessibility challenges. This presentation shows how far these archival records filled the data gaps in reconstructions for 4 centuries of sunspot group numbers and sunspot positions as well.