Latest sunspot drawing and USSPS file

01 December 2023

All daily drawings of the sunspot groups and USSPS produced by INAF - Catania Astrophysical Observatory are available in this page.

When the weather conditions permit, daily drawings of sunspot groups and pores are maken by a Cooke refractor (150mm/2230 mm) on a 24.5 cm diameter projected image of the Sun.

These drawings are used to determine some charcteristics of the SunSPotS groups visible on the photosphere and to report them in form of a numerical code (ursigram), named USSPS.