Historical solar Ca II K observations at the Rome and Catania observatories
arXiv:1902.07483 · doi:10.1393/ncc/i2019-19005-2
Abstract
Here we present the little explored Ca II K archives from the Rome and the Catania observatories and analyse the digitised images from these archives to derive plage areas.
5 pages, 3 figures, to be published in "Nuovo Cimento C" as proceeding of the Third Meeting of the Italian Solar and Heliospheric Community