The sun’s crown

The sun’s crown – The solar corona is the outermost part of the solar atmosphere above the chromosphere (see here), which is called the solar corona. It is observed, as it does not have clearly defined boundaries and varies depending on external conditions, a changeable radiant glow around the Sun. The shape and brightness of the solar corona depends on the degree of activity of the Sun. The indicator of maximum illumination that it can provide during a total eclipse of the Sun on the earth’s surface is less than the indicator of illumination that the full Moon gives. The largest part of the corona, towering above the sun by 0.5-1.0 solar radius (or more), is called the inner corona. It reaches heights of several radii of the Sun during increased solar activity. Significantly lower is the so-called outer corona, which extends to the Earth’s orbit and has a less bright color.
The corona is a collection of spicules and prominences scattered in the circumlunar space, which are components of the corona. Its rarefaction is one hundred billion times greater than that of the Earth’s atmosphere. The temperature in the lower part of the corona, on a relatively small area of the surface, increases from tens of thousands to a million degrees. It has been found that there are two main ways to heat the corona.
The first of them is due to the redistribution of the energy of sound waves, which are the result of granulation (see here). At the same time, by themselves they are not able to spread beyond the chromosphere. But the propagation of the energy of sound waves into the coronal zone is carried out by converting them into Alvenov waves. These are transverse magnetic-hydrodynamic waves, which have the shape of waves with a longitudinal orientation, which propagate along the magnetic field (see electromagnetic field, physical field) without significant energy losses. In the case when the magnetic tube (see Solar, magnetic power tubes) contributes to the removal of Alvenov waves to a sufficiently high altitude, their reverse transformation into sound waves occurs, which heat the corona, as it happens in the chromosphere.
This second mechanism of corona heating is associated with the redistribution of energy, which is released during multiple solar flares of different power (see Solar flares).
It is the high temperature of the corona, due to the presence of ionized ions and free electrons in it many times, that contributes to the presence of numerous ionized ions and ions with electrons in it. Some atoms lack from 9 to 12 electrons. In general, on average, the plasma substance is electrically neutral – the total positive charge of ions is equal to the total negative charge of free electrons.
The corona glow is due to the photospheric radiation scattered on free electrons, which can be seen here. Radiating with the help of radio waves, it emits as a completely black body with a temperature of about a million degrees. But the corona is also a powerful source of X-ray radiation (see Electromagnetic radiation, non-thermal), which occurs as a result of the interaction of charged particles with magnetic fields.
The inner corona consists of interplanetary dust, which scatters the sun’s rays and promotes the spread of the solar wind. The solar wind, which reaches the boundaries of the Solar System, is a natural extension of the corona.