Final answer:
The coronal gas refers to the gases in the Sun's outer atmosphere, known as the corona. It is characterized by its low density and is responsible for the production of the solar wind. The solar wind predominantly emerges from dark regions called coronal holes.
Step-by-step explanation:
The coronal gas refers to the gases present in the Sun's outer atmosphere, known as the corona. The corona is a region that extends for millions of miles in all directions from the surface of the Sun. It is characterized by its low density, with only about 10⁹ atoms per cubic centimeter at the bottom of the corona.
One of the most remarkable features of the corona is the solar wind, a stream of charged particles (protons and electrons) that flow outward from the Sun into the solar system. The solar wind is produced by the hot and rapidly moving gases in the corona, which cannot be held back by solar gravity.
The solar wind predominantly emerges from dark regions of the corona called coronal holes, where gas can stream away from the Sun uninhibited by magnetic fields. On the other hand, hot coronal gas is mainly present in regions where magnetic fields have trapped and concentrated it.