Big M9 solar flare

The Sun unleashed one of the biggest flares of the year this evening. An M9 class flare (next size up is the biggest type - X) erupted off the SE edge of the solar disc. It was large enough to break through the post sunset ionosphere here in Birr and disrupt the VLF radio signal from Cutler, Maine. These size flares are rare and maybe a sign of an active sunspot turning to face Earth. Below is a plot from my solar flare monitor. Live data (during daytime hours) is available at www.davegradwell.com/solarflares.html

Dave Gradwell