Iris View of Sun's Active Region (IMAGE) Center for Astrophysics | Harvard & Smithsonian Caption This image from the Interface Region Imaging Spectrograph (IRIS) shows emission from hot plasma (T ~ 80,000-100,000 K) in the Sun's transition region -- the atmospheric layer between the surface and the outer corona. The bright, C-shaped feature at upper center shows brightening in the footprints of hot coronal loops, which is created by high-energy electrons accelerated by nanoflares. The vertical dark line corresponds to the slit of the spectrograph. The image is color-coded to show light at a wavelength of 1,400 Angstroms. The size of each pixel corresponds to about 120 km (75 miles) on the Sun. Credit NASA/IRIS Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.