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AAVSO Sunspot Count Data

We recently released a significant update to the backend systems for the AAVSO website. While most of the bugs introduced by this update have been fixed, there may still be problems we haven't fixed. If you run into a problem, please email webmaster@aavso.org

Use this form to access the American Relative Sunspot Number (Ra) as published by the National Geophysical Data Center (which is shut down pending a Federal budget agreement). These numbers reflect what was published by NGDC, and may contain typographical errors. For the official AAVSO value of Ra, see the AAVSO Solar Bulletin for specific month(s) you are interested in.

Month
Year
Output type Web page          CSV file
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