What is Chromosphere?
The chromosphere is the transition zone between the corona and the photosphere. It is basically the red and shining layer of gas above the Sun’s photosphere. It is the second layer of the atmosphere of Sun with photosphere as the first one and corona the third. It is about 2000-3000 km deep and of very low density which makes its visibility very poor. Low visibility is also attributed to the excessive brightness of the photosphere. It is generally seen only during a complete solar eclipse when the photosphere is hidden by the moon and the chromosphere is seen underneath.
The temperature of Chromosphere ranges from 6,000-20,000 degree Celsius and it increases as the Chromosphere moves away from the Sun. Spicules or long-thin gaseous spikes are present on its edges. The Chromosphere has emission lines along its spectrum. H-alpha lines are the strongest of the emission lines. It is the burning of the H-alpha lines at very high temperatures which are seen as a red rim during the total solar eclipse.