The DXZone.com Amateur Radio Internet Guide
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Daily Sunspots groups
Posted:
https://www.dxzone.com/dx34362/daily...ts-groups.html
Propagation/Sunspots
All daily drawings of the sunspot groups and USSPS produced by INAF -
Catania Astrophysical Observatory from 2009 up today are available in this
page. The 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.