(middle layer of the Sun's atmosphere)
The chromosphere is the layer of the Sun's atmosphere outside
the photosphere and inside the solar transition region.
It is about 2000 kilometers deep and its density is
a hundred millionth that of the Earth's atmosphere.
The inner boundary is 6000 K and the outer boundary is 35000 K.
The chromosphere is visible during a solar eclipse.
The term plage is used for certain kinds of bright
regions of the chromosphere. They occur near sunspots.
Referenced by pages:
Coronal Solar Magnetism Observatory (COSMO)
High Altitude Observatory (HAO)
chromospheric activity index
standard model of a flare
Sun surface features