Alternate Definitions for Corona

The sun's dynamic atmosphere is called the corona. It is filled with electrically charged particles, whose movements are governed by the tangle of magnetic fields surrounding the sun. While the sun's surface is 6000K, the corona can reach up to millions of degrees, sparking questions from researchers on mechanisms heat the atmosphere so dramatically. Solar flares and coronal mass ejections originate in the corona.

The outermost atmospheric region of the Sunor a star, characterized by ionization temperatures above 10^5 K. The solarcorona starts at about 2100 km above the photosphere; there is no generallydefined upper limit.

The outermost atmospheric region of the Sun or a star,
characterized by ionization temperatures above 10^5 K.
The solar corona starts at about 2100 km above the
photosphere; there is no generally defined upper limit.