Deep Into Solar Minimum, The Sun Surprises

The news around the ham radio circles I hang out in is that an active sunspot region has rotated to the Earth-facing side and is crackling with activity.  Sunspot group 2740, part of current cycle 24, was visible a month ago and irradiated Earth with loud shortwave radio bursts before rotating out of view.

After the nearly two weeks to transit the far side of the sun, it's back and doing it again.

"Yesterday, May 6th, was an incredible day of strong solar radio bursts including one of the strongest of the current solar cycle," reports Thomas Ashcraft who recorded the outburst with a shortwave radio telescope in New Mexico.

Click here to listen to the noise depicted in this time/frequency plot.  No, seriously.

Ashcraft adds

"This one really rips," he says. "I recommend listening with headphones. It is a stereo recording with 20 MHz in one channel and 25 MHz in the other."
...
"In the dynamic spectrum, note the 'feathery' upward drifting radio emissions," he says. "I've never seen anything like that--not even during solar maximum. This is auspicious and rare activity to be happening during the deepest time of solar minimum."

I'm going to go out on a limb and say that most of you didn't know that radio astronomy was a hobby and there were radio astronomers who listened to noise as a hobby.  It doesn't require a giant, steerable dish antenna, either.  The sun is a constant source of noise over wide chunks of the radio spectrum and sometimes it does things a bit more dramatic than others.  Jupiter is a commonly heard source of noise in the High Frequency spectrum, common enough that commercial home radio telescopes are a thing.  These are named after a NASA education project: Radio JOVE. 

Getting back to the original topic, that the Sun has surprised observers by doing something never before seen by this observer (Thomas Ashcraft) during the beginning of a what looks to be a deep solar minimum, this is what makes the field something to keep an eye on.  Even though solar activity has been very low most of this year, it's still capable of developing an active sunspot region.