A compact grating spectroheliograph for the Mgii resonance lines

McDowell, M. W.

doi:10.1007/bf00153889

Cited by 2 publications

(1 citation statement)

References 8 publications

(3 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, since finding information about old Ca II K observations is not straightforward, there is a high chance that the list of archives in Tables 1, 2 is not complete. For instance, Bates and McDowell (1972) had presented a spectroheliograph for operation on a rocket or balloon and showed example observations in the Ca II K line. However, besides one observation included in their paper, it is unclear how many observations were performed or whether they have survived to this day.…”

Section: Digitisationmentioning

confidence: 99%

Full-disc Ca ii K observations—A window to past solar magnetism

Chatzistergos

Krivova

Ermolli

2022

Front. Astron. Space Sci.

View full text Add to dashboard Cite

Full-disc observations of the Sun in the Ca ii K line provide one of the longest collections of solar data. First such observations were made in 1892 and since then various sites around the world have carried out regular observations, with Kodaikanal, Meudon, Mt Wilson, and Coimbra being some of the most prominent ones. By now, Ca ii K observations from over 40 different sites allow an almost complete daily coverage of the last century. Ca ii K images provide direct information on plage and network regions on the Sun and, through their connection to solar surface magnetic field, offer an excellent opportunity to study solar magnetism over more than a century. This makes them also extremely important, among others, for solar irradiance reconstructions and studies of the solar influence on Earth’s climate. However, these data also suffer from numerous issues, which for a long time have hampered their analysis. Without properly addressing these issues, Ca ii K data cannot be used to their full potential. Here, we first provide an overview of the currently known Ca ii K data archives and sources of the inhomogeneities in the data, before discussing existing processing techniques, followed by a recap of the main results derived with such data so far.

show abstract

Section: Digitisationmentioning

confidence: 99%