Skip navigation

A careful restudy of the sunspot numbers reported by dozens of solar observatories around the globe and averaged in the Solar Influences Data Analysis Center at the Royal Observatory of Belgium has found some discrepancies, often based on individual observers’ idiosyncrasies. (See Section 10.2, p. 265 and Figure 10-18a, p. 268.)

The Center has provided the following revised sunspot count for this revision of The Cosmos, 4th ed.  It is updated, too, past the recent solar maximum, which peaked at different times in different solar hemispheres.


Credit: SIDC, Royal Observatory of Belgium

Links: Read more about their analysis and download comparison figures.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: