Skip to main content

solar observing

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.

Solar Observing Guide in Italian

We now have available for download a translation of the AAVSO Solar Observing Guide into Italian - thanks to the excellent volunteer work of Raffaello Braga. This Guide is available free-of-charge and all solar observers are strongly encouraged to read it.

In addition to Italian, the Guide is available in English, French, German, Spanish (and soon Portuguese).

Solar Observing Guide in Spanish

Thanks to the excellent work of our own Sebastián Otero, we now have a Spanish translation of the AAVSO Solar Observing Guide available for download free-of-charge. In addition to Spanish, this Guide is also available in French and German (and soon Italian).

If you would like to translate the AAVSO Solar Observing Guide or any of the other AAVSO observing manuals or guides into your own native language, please contact AAVSO staff member Sara Beck.

Solar Observing Guide - in French

Thanks to a wonderful volunteer effort by Bernard Candela, we now have available a French translation of The AAVSO Solar Observing Guide!  Many thanks Bernard!


SunEntry - A sunspot data entry program

SunEntry is a data entry program for solar observers. It will help you to create reports and send them to our database where they will be used in the AAVSO American Relative Sunspot Program. The information you submit will also be used in the monthly Solar Bulletin.

Getting Started

Before you can use SunEntry, you must have an AAVSO website account and an AAVSO Observer code if you don't already have both. Here are instructions on how to get them:

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?

The Gyrator III VLF Receiver

The latest version of the Gyrator series of VLF receivers (first developed in the 1990s) is the Gyrator III, a revision of Arthur Stokes' Gyrator II by Guglielmo Di Filippo (observer A-93).

Circuit diagrams and wiring for the Gyrator III are available here in Microsoft Word and PDF formats: .doc, .pdf

AAVSO Sudden Ionospheric Disturbance Program Observers

Active Observers (Data submitted within the last year)

OBS ID Observer Name Station Location
A-94 Al McWilliams St Cloud, MN
A-96 Roberto Battaiola Milan, Italy
A-97 Jon Wallace Torrington, CT
A-118 Lionel Loudet Muret, France
A-120 Bob Terrill Ballarat, Victoria, Australia


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