CHATZISTERGOS, THEODOSIOSTHEODOSIOSCHATZISTERGOSERMOLLI, IlariaIlariaERMOLLIFALCO, MARIACHIARAMARIACHIARAFALCOGuglielmino, S. L.S. L.GuglielminoKrivova, N. K.N. K.KrivovaROMANO, PaoloPaoloROMANOSolanki, Sami K.Sami K.Solanki2021-02-172021-02-1720192037-4909http://hdl.handle.net/20.500.12386/30420Here 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.STAMPAenHistorical solar Ca II K observations at the Rome and Catania observatoriesArticle10.1393/ncc/i2019-19005-22-s2.0-85066121337000470259000003https://www.sif.it/riviste/sif/ncc/econtents/2019/042/01/article/42019NCimC..42....5CFIS/05 - ASTRONOMIA E ASTROFISICA