The Chromosphere

Click on image for full size (164 K GIF) H alpha image from the National Solar Observatory at Sacramento Peak

Above the photosphere is the chromosphere, a region about 2500 kilometers thick. Just prior to and just after the peak of a total solar eclipse , the chromosphere appears as a thin reddish ring. The conspicuous color of the chromosphere (compared to the mostly white corona) led to its name (meaning ``color sphere.'') The chromosphere is most easily viewed in emission lines such as Hydrogen alpha, where bright regions known as plages, and dark features called filaments are visible. Filaments are the name given to prominences when they are seen on the solar disk. Spicules are visible in the chromosphere on the limb of the sun. They are jets of plasma shooting up from supergranule boundaries.