The Quiet Chromosphere and Corona

Abstract

The chromosphere is a very thin layer of plasma, 5000 to 10000 km thick, directly covering the photosphere (Figure 1). It may be studied especially during total solar eclipses and, in fact, was discoverd during one. When the moon has covered the entire photosphere the chromosphere remains for a few seconds as a luminous coloured arch. This colour is the origin of the name “chromosphere”.