This archive, obtained at the solar tower of the Arcetri Astrophysical Observatory, contains full-disk solar images, in JPG format, (510 x 680 px), resulting from the digitization of plates of CaII K and Hα spectroheliograms acquired during 5042 observing days at the Arcetri G.B. Donati tower from 1926 to 1974.

The images available through this visualization are compressed format and smaller than those originals for a rapid transfer and easy viewing.


The history

The digitized archive

Image processing

Photographic calibration


JPG Archive