Experts Struggle to Understand Mysterious Sunspots

Vivid images of a sunspot formation in action has revealed startling new clues that may help scientists understand how and why these unusual phenomena occur on the surface of the Sun.

Sun spots have long been a mystery to solar experts. They have theorized that these dark blemishes on the Sun's surface occur when clashing magnetic fields form dense regions that prevent heat from rising from the Sun's interior. The spots range from small moon-sized structures to Jupiter-sized ones. They also tend to be comprised of a dark, "cool" center called the umbra - where the magnetic suppression of solar activity is the strongest - and the outer penumbra, where it is warmer and lighter.

These unusual phenomena were studied by ancient Chinese men of science and even the famous Galileo, according to NASA. But even today, experts are still unsure how they form and how they keep their incredibly stable magnetic structure for so long.

Yesterday, researchers from the New Jersey Institute of Technology (NJIT) presented new and exceptionally detailed images of a sunspot formation at the 224th meeting of the American Astronomical Society (AAS), held in Boston.

According to the team, images compiled from the Solar Telescope at Big Bear Solar Observatory (BBSO) in California and NASA's IRIS - an unmanned orbital telescope - have revealed the complex workings of internal magnetic fields that keep sunspots so stable.

Researchers explain that the vivid images show subtle activity in the area where the umbra and penumbrae of a spot meet, appearing like a "rolling motion" of plasma contained by magnetism. These images provide the first detailed view of such a mechanism, and suggest that rapidly rotating convective rolls in the penumbra are connected to similarly rotating relatively bright "umbral dots" found deeper in the darker part of the spot.

Plasma jets also will occasionally occur as well in a seemingly spontaneous manner, indicating that these spots are not nearly as "tame" as thier dark surfaces would indicate.

While these new observations do not fully explain how any of this activity occurs, it does tell researchers that the spots are much more complex than previously thought and not as static as earlier images would imply.

A BBSO press release detailing the new observation was released on June 2. The researchers' presentation can be viewed more in detail here.