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.
3 minutes 34 seconds 3.3 MB
This 1255 UT sound specimen "roller coasters" with numerous sharp peaks.
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. )
Click arrow below for a full collection of solar specimens