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Solar Radio Observing
By Jon Wallace, email wallacefj_at_comcast_dot_net
Solar Flares & Prominences
Solar Flares and the Ionosphere
Solar Flares are a tremendous explosive burst of light and material from the sun. A flare gives off as much energy as the earth consumes in 100,000 years. This energy can affect the Ionosphere, changing the height of the D, E and F layers and affects communications, etc.
Sudden Ionospheric Disturbances (SIDs)
The flare-induced changes in the Ionosphere can be detected using various radio frequencies. The AAVSO has chosen to use VLF. I use the 24.0 KHz signal from Cutler, Maine.
The AAVSO Radio & Antenna
Check out the AAVSO site for all the relevant information and schematics:
Far Circuits sells a circuit board for this project for about $7 (details on the site). It makes it a lot easier to build the project. Most parts are available from Radio Shack or Mouser Electronics. I used a ten-turn potentiometer for the tuning so I can get better control. The antenna is easy to make but consists of 125-200 turns of wire!
Detected flares are generally caused by X-ray flares and have various flux levels associated with them (see chart below). The radio detection records a peak (or a trough as in my case) when a flare is detected (see graphs below).
To join the AAVSO Solar Radio group simply register on-line. You are given a number and a program to use to facilitate sending the data the group leader and the data is made into a monthly chart.
Charts and other solar data for the month are available from:
Please feel free to contact me for more information, questions, or comments.
X-ray Class x = peak flux in the 0.1 to 0.8 nm range
|X-ray Class||In mks system
|In cgs system
|A||< x 10-7||x 10-4|
|B||10-7 <= x 10-6||10-4 <= x 10-3|
|C||10-6 <= x 10-6||10-3 <= x 10-2|
|M||10-5 <= x 10-6||10-2 <= x 10-1|
|X||10-4 <= x||10-1 <= x|
Integrated flux from start to end, in joules m E-2.
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