An X-ray Flare

An X-ray Flare

. As shown in the lower left of this X-ray image, a solar flare can result in soft X-ray radiation that outshines the entire Sun at these wavelengths. Less luminous coronal loops are found in quiescent, or non-flaring, active regions on other parts of the Sun, and dark coronal holes are also present at both poles (top and bottom). This image was taken with the Soft X-ray Telescope (SXT) aboard the Yohkoh satellite on 25 October 1991. (Courtesy of Keith Strong, NASA, ISAS, the Lockheed-Martin Solar and Astrophysics Laboratory, the National Astronomical Observatory of Japan, and the University of Tokyo.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University