AAVSO Sunspot Count Data
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.
Last Updated: October 14, 2013 - 9:11am