© Discovery News
As the sun continues to ramp up in activity after a long period in the doldrums, solar astronomers have been treated to an up-tick in sunspot numbers, solar prominences and flares.

And now, radio astronomers have joined the fun, listening to the roar of a particularly "noisy" sunspot currently pointing in our direction.

Not all sunspots emit strong radio emissions, but sunspot 1057 certainly isn't shy. As reported by, a radio astronomer in New Mexico received a mix of Type III and Type V radio emissions:
"It was sunspot 1057. All day long it had been producing small radio bursts around 21 MHz. Then, at 1813 UT, it let loose a big one. The burst only lasted a minute, but it saturated the radios." --Thomas Ashcraft, radio astronomer.
But why are these radio bursts important? Primarily, they give solar physicists an idea about the extreme magnetic fields and plasma conditions inside sunspots. Sunspots are produced when vast magnetic fields push through the surface of the sun, pushing the uppermost layer of the sun's body (the photosphere) away, exposing the cooler (thus darker) solar interior.

("Cooler" is a misnomer, nothing on the sun can be termed "cool." But when compared with the photospheric temperature of approximately 6,000 Kelvin, a sunspot interior can be as low as 3,000 Kelvin.)

As sunspots contain very intense magnetic fields, clouds of charged particles (plasma) are confined and injected along these fields. Often flares result, exciting electrons trapped in the plasma. As electrons accelerate (often to velocities close to the speed of light) and oscillate, they can generate intense radio waves.

Type III and Type V radio bursts are pretty much the same thing apart from differing periods; Type III emissions last for longer, whereas Type V's are more bursty and associated with intense flare activity.

Besides what they are and how they are generated, the coolest thing about these radio events is how they sound: Listen to Thomas Ashcraft's recording of the radio emissions from sunspot 1057 (sounds like the "whoosh" of a rainstorm hammering down on my shed roof).

If you want to become a solar radio astronomer too, NASA runs a program called Radio JOVE that will help you set up your own radio telescope for less than $200. I think I know what my next space project will be...