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 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).
Active Observers (Data submitted within the last year)
|Torrington, CT, USA
|le Vauroux, France
VERY LOW FREQUENCY (VLF) RADIO STATIONS Station Station Frequency Radiated Site ID (kHz) Power (kW) U.S.
Solar Program, Reducing Data and Email Format
Reducing Data Gathered by VLF Monitoring Systems
(Extracted from SID Technical Bulletin Vol. 3, Number 4, Oct. 1992)
SID Monitoring Overview
AAVSO SID Program
Rodney Howe, Solar Section chair & SID leader
So, what are we looking for? Here are a couple references of SID events and their influence on the ionosphere:
The Zurich Classification System of Sunspot Groups
Contributed by Tom Fleming (FLET)
"A" Type: One or more tiny spots that do not demonstrate bi-polarity or exhibit penumbra.
"B" Type: Two or more tiny spots that demonstrate bi-polarity but do not exhibit penumbra.
Contributed by Carl E. Feehrer (FEEC)
Revised August 2000
ACCURACY AND CONSISTENCY IN THE PRODUCTION OF THE AMERICAN SUNSPOT NUMBER (Ra)
Contributed by Carl E.
Guidelines for New Solar Observers
- Do not look directly at the sun without the protection offered by a filter. For naked eye viewing, a piece of #14 welder's glass provides adequate protection. Do not use overexposed film, dark glasses, or other media that are not designed specifically for solar viewing.