The Sun’s corona, which is like the Sun’s atmosphere, although hotter than its interior, is less dense and therefore emits fewer photons. Therefore, in normal times, the Sun’s surface shines so brightly that it obscures the corona. Only when there is a total solar eclipse does the solar disc get ‘occulted’ by the moon, exposing the corona to our view, albeit using instruments for photographing it.

The Sun’s magnetic field lines stretch out from the surface and permeate the corona. Solar plasma wind and storms including flares and coronal mass ejections are born in coronal magnetic field. Emergence of magnetic field from below the Sun’s surface and dynamic restructuring in the outer layers changes the shape of the corona.