Corona

Corona, outer atmosphere of the sun or other stars. The term is used also for the halo seen around a celestial body due to diffraction of its light by water droplets in thin clouds of the earth's atmosphere, and for a part appended to and within the corolla of some flowers. Around high-voltage terminals there appears a faint glow due to the ionization of the local air. The result of this ionization is an electrical discharge known as corona discharge, the glow being called a corona.

See also: Star.