Multi-wavelength observations of sunspots with the 1.6-meter New Solar Telescope at Big Bear Solar Observatory (BBSO) in California and aboard NASA's IRIS spacecraft have produced new images of high-speed plasma flows and eruptions extending from the Sun's surface to the outermost layer of the solar atmosphere, the corona.
Operated by New Jersey Institute of Technology (NJIT), BBSO houses the largest ground-based telescope dedicated to solar research.
The high-definition video acquired at BBSO provides unique 3D views of a sunspot, revealing rapidly rotating plasma rolls, powerful shocks, and widespread plasma eruptions driven by solar-energy flux and controlled by intense magnetic fields. These leading-edge observations show that sunspots are far more complex and dynamic than previously believed.
Sunspots, first seen by Galileo more than 400 years ago as dark blemishes on the Sun, are still one of the greatest mysteries of astronomy. It has been known for more than a century that sunspots are compact, concentrated magnetic fields and that they appear dark because the magnetism prevents heat from rising to the surface from the superhot interior. But why these magnetic fields become so concentrated and compacted in structures that remain stable for days and sometimes weeks in a very turbulent environment is a mystery.
Sunspots can be the size of Earth or as big as Jupiter. Typical sunspots are nearly round with a very dark and relatively "cold" umbra (7,000 degrees Fahrenheit compared to the 10,000-degree solar surface) surrounded by a less dark and warmer penumbra. However, there are no external forces on the Sun that could hold these giant magnetic structures together.
They appear and are organized by their own induced forces. Understanding the processes of such self-organization in the hot turbulent plasma is of fundamental importance for physics and astrophysics.
