David Hathaway, National Aeronautics and Space Administration, Marshall Space Flight Center
This resource describes the discovery of sunspots and early efforts to keep track of their numbers. Students will discover that there are actually at least two official sunspot numbers reported. The International Sunspot Number is compiled by the Sunspot Index Data Center in Belgium. The NOAA sunspot number is compiled by the National Oceanic and Atmospheric Administration. The numbers tabulated on-line at this site are the monthly averages (SSN) and standard deviation (DEV) derived from the International Sunspot Numbers. The site also describes the Maunder Minimum in the number of sunspots and the butterfly diagram pattern exhibited by the location of the sunspots on the surface of the sun. There is a link to future predictions of the number of sunspots by scientists at the Marshall Space Flight Center based on characteristic behavior in the past.
This description of a site outside SERC has not been vetted by SERC staff and may be incomplete or incorrect. If you
have information we can use to flesh out or correct this record let us know.