The Radio-Sun

When there is a solar flare on the Sun's surface, there is often an accompanying burst of radio energy projected into space. You can monitor these bursts with standard short wave and vhf receivers with modest antennas. The receiver should be able to detect AM (amplitude modulated) signals. FM receivers are not good for this purpose. A pre-amplifier between the antenna and the receiver will help things greatly at vhf, but on frequencies below 30 MHz, a preamp is probably not necessary. A good and inexpensive candidate for a vhf solar flare receiver might be an aircraft band radio which covers the 120-140 MHz range. Ramsey electronics sells an inexpensive kit. A small 3 or four element Yagi antenna pointed towards the sun should be adequate if a preamplifier is used.

The solar burst shown above was recorded at 20.1 mHz with very simple equipment on June 10, 2000 by Wes Greenman, engineer of the University of Florida Radio Observatory. Wes used a Radio Jove receiver and dual dipole antenna to record the solar burst which appears as the prominent hump on the left side of the chart. The stair-stepped signal on the right side of the chart is a calibration signal.

Solar radio bursts are classified as follows:

Type I Short, narrow band events that usually occur in great numbers

together with a broader band continuum. May last for hours or days.

Type II Slow drift from high to low frequencies. Often show fundamental

and second harmonic frequency structure.

Type III Rapidly drift from high to low frequencies. May exhibit harmonics.

Often accompany the flash phase of large flares.

Type IV Flare-related broad-band continua.

Type V Broad-band continua which may appear with III bursts. Last 1 to 2

minutes, with duration increasing as frequency decreases.

Burst Examples

Type II

Type III

09/23/2000

04/02/2001 Class 20 Xray Flare

04/06/2001 Class 5 Xray Flare

06/08/2003 Radio Spectrograms from WCCRO Type II and X-ray with sound

The Shark Fin Signature and a False Shark Fin

Detection by Ionospheric Effects

Magnetic Storms

Thermal Emissions

Solar Links

Free Spectrograph Software allows real-time monitoring of Jupiter and Solar storms from UFRO and WCCRO.

Green Bank Solar Spectrometer

NOAA FTP site with recent radio burst info.

Daily updated ACE data which you can compare to your radio observations.

Marshall Space Flight Center Solar Physics

List of TYPE II/III/IV bursts from WAVES/WIND satellite.

Bruny Island Radio Spectrometer - 3 to 45 MHz in Tasmania.

IPS Australian solar site.



Hiraiso Solar Terrestrial Research Center, a Japanese radio site.

ETHZ PLASMA AND RADIO ASTROPHYSICS GROUP, a European site.

Daily images in different wavelengths:

http://umbra.nascom.nasa.gov/images/latest.html

National Solar Observatory / Sacramento, Peak NSO CORONAL DATA.

http://www.bbso.njit.edu/cgi-bin/LatestImages

Spaceweather.com

Thanks to Tom Ashcraft for many of the above solar links!