Until the advent of Earth-orbiting satellites like Skylab, x-ray views of the Sun were impossible (remember that the EarthΓÇÖs atmosphere absorbs most x-ray emissions). X-rays are produced in the SunΓÇÖs hottest region, the corona. The photosphere and chromosphere, too cool to produce this type of light, are not seen here. The bright areas in this photograph are associated with magnetic fields that form closed loops and trap very hot, x-ray producing gas. Each loop begins in the photosphere, at one magnetic pole of a sunspot, and reaches far into the corona before returning to the photosphere to connect with the sunspotΓÇÖs opposite pole.
The dark areas at the top and bottom of the image, known as
