Chromosphere

A lower layer of a sun's atmosphere, the chromosphere is the transition between the photosphere and the corona.

In a typical main sequence dwarf star, the chromosphere is 2000 - 3000 km thick. It glows faintly relative to the photosphere and is very difficult to see apart from when a total solar eclipse occurrs. The temperature rises from 6 000 K to about 20 000 K. At these higher temperatures hydrogen emits light that gives off a reddish color (H-alpha emission), which can be seen on the prominences which are ejected from the surface.