The solar corona, the outermost part of the Sun’s atmosphere, has always been an object of interest to astronomers. Its high temperature of millions of degrees and strange behavior have attracted the attention of scientists from all over the world. But only now, thanks to the SolO solar orbiter, we can see this mysterious region of the Sun in unprecedented detail.
An international team of astronomers using SolO has discovered a previously unseen feature of the solar corona – “shooting stars” falling on the Sun. These meteoroid-like fireballs are up to 250 kilometers wide and cause explosive gas bursts as they collide with the surface of the Sun.
The coronal shower is not composed of water, as its name suggests. The solar corona is composed of plasma, an ionized gas that has a very high temperature. Sometimes the temperature drops in this region and the plasma condenses to form clots. However, even these clots have temperatures of tens to hundreds of thousands of degrees.
The enormous gravitational force of the Sun attracts these clots to itself at speeds of up to 100 kilometers per second, creating a fireball effect. As a result of the collision with the surface of the Sun, explosive gas bursts occur, which propagate through the corona, reheating it. It is a kind of “shooting star on our star,” according to Dr. Patrick Antolin of Northumbria University.
Observations of the coronal rain were made with SolO, which was at the first perihelion of its orbit, the closest point to the Sun. Because of this position, the instrument was able to see the solar corona in unique detail. One of the SolO instruments was able to detect that coronal rain is present everywhere in the active regions of the Sun.
The Sun’s fireballs are different from the meteors we see on Earth. Meteors are created by rocky or icy materials that burn as they enter Earth’s atmosphere, leaving bright trails. In contrast, solar fireballs are compressed by magnetic fields and follow them on their way to the Sun’s surface. This makes them harder to identify without a tail.
The Sun’s magnetic field is too strong to allow material to go back or separate and form a tail. Instead, they fall into the Sun, creating explosive bursts of gas. This bright phenomenon can only be observed from below, since the solar corona is very bright.
The discovery of coronal rain and its properties opens up new horizons for studying the Sun and its atmosphere. It allows scientists to better understand the processes occurring on the surface of our star and their influence on the surrounding space.
