May 19 2007

Sounds of a Flare, a Disappearing Solar Filament Event,
and Type II and Type V Radio Emissions All at Once

Strong Radio Emissions

Observer's Notes:  May 19, 2007   There was a small solar flare and a "disappearing solar filament" at 1252 UT.
1252 UT is 6:52 am New Mexico time and the Sun was just coming up here in the mountains. These events caused
very strong bursting and I was lucky to catch its full power which was peaking at the heart of my observing frequencies.

These two sound files are a mix of Type II and Type V emissions.
Recorded in stereo at 21.1 MHz and 20.971 MHz

This file has strong Type V solar emissions beginning at 1301 UT. See definition of Type V below.
SMay19071301ut21MHzTypeV.mp3      3 minutes 34 seconds      3.3 MB

This 1255 UT sound specimen "roller coasters" with numerous sharp peaks.  
SMay19071255ut2120TypeII.mp3   1 minute  59 seconds       1.8 MB


Type II solar radio emissions are shock waves caused by chromospheric eruptions, travelling from the solar corona out towards the
interplanetary medium at a velocity of about 1000 km/s. They move slowly from high to low radio frequencies in a few minutes' time;
they are thought to be caused by plasma oscillations induced by the passage of the shock wave.

Type V radio emissions are attributed to high energy electrons enclosed in coronal magnetic arcs.

( Image above is a composite of three spectrographs of this particular emission event from Nancay Observatory, France. )

Thomas Ashcraft


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