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sunspot

Solar Section

Welcome to the web pages of the AAVSO Solar Section, a world-wide group of observers dedicated to observing the closest variable star in the sky -- our own Sun!

What are sunspots?

The term "sunspot" appears in the news, often in connection with stories on aurorae, electrical outages, and problems with orbiting satellites.  But often these stories don't really explain what sunspots are and why they're of interest to us on Earth.  So what are sunspots?

SID Database

About the SID database

The Sudden Ionospheric Disturbance (SID) Database lists all events identified in the AAVSO Solar Bulletin. These results are provided monthly by the worldwide network of SID observers in the AAVSO Solar Division. Individual results are correlated with other observers' reports and reduced to a list of events with high definiteness ratings.

Accuracy and Consistency in the Production of the American Sunspot Number (Ra)

Addendum

ACCURACY AND CONSISTENCY IN THE PRODUCTION OF THE AMERICAN SUNSPOT NUMBER (Ra)

Contributed by Carl E. Feehrer (FEEC)

Solar Photo Gallery

Here are a number of solar photographs obtained by AAVSO solar observers over many years.  Thanks to all of the photographers for sharing their images with us!

 

 

Atmospheric seeing conditions for solar observing

Atmospheric Seeing Conditions

Contributed by Tom Fleming (FLET)

Reports and observations submitted to the AAVSO use the following ratings for atmospheric turbulence (Seeing): Poor, Fair, Good and Excellent.

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484