There Are Tiny Bright Dots All Over The Sun, And We May Finally Know Their Source

There are other speckles decorating the dynamic face of our Sun. Solar physicists have been studying tiny, fleeting speckles of brightness that emerge and fade in less than a minute on average in regions where loops of plasma rise from the solar surface.

They are named solar dots. The analysis has shown that the fleeting phenomenon is likely the result of magnetic shenanigans, which wouldn't be hugely surprising given that magnetic field changes play a huge role in all sorts of wacky solar phenomena.

The finding suggests the Sun is more complex than we thought, and that analysis of the sun freckles could help us understand the magnetic field.

When the Sun had just entered a new cycle and was growing more active, the fascinating dots were spotted in images from the joint NASA-ESA Solar Orbiter.

The magnetic loops that were seen on 20 May 2020 were from the solar photoosphere.

The solar magnetic field is not easy to understand. The motion of a convecting, conducting fluid in the solar interior causes electric and magnetic fields. The resulting magnetic field lines are complex and numerous.

Sunspot are regions where magnetic fields are strong, and solar flares and coronal mass ejections are produced by magnetic field lines snapping and connecting.

When the solar magnetic poles switch places, the 11-year solar cycles are driven by the magnetic field reversal.

A team of scientists took a closer look at one of the magnetic flux regions, which were imaged in extreme ultraviolet wavelength. There were small, round specks of brightness hidden in the solar plasma.

The team was able to study the dots in detail because of image processing. Around 170 dots were observed and characterized over the course of an hour.

The dots were around 700 kilometers in diameter and were around 30 percent brighter than the surrounding plasma, and lasted just 50 seconds before disappearing again. Half of the dots remained isolated for the duration of their brief lives, while the rest split into two and formed explosives.

The data from NASA's Solar Dynamics Observatory showed that the dots appeared in the entire field of view, but were more densely clustered in more magnetically active regions.

The next step was to figure out what causes the speckles. The software that was used to model the solar atmosphere was Bifrost.

The dots may be moments of magnetic reconnection between the magnetic field lines that are emerging from the solar surface and the magnetic field lines that are descending into it.

Many dots stretch into an extended loop because of magnetic reconnection in the solar atmosphere.

Some of the dots did not show up in regions with magnetic fields, which suggests there may be more than one formation pathway for these mysterious features. The team said that the propagation of magnetoacoustic waves in the solar plasma could cause shocks that result in dots.

The mystery is not solved. There are other dots on the Sun, and they have been observed in different environments.

Future research could help to resolve these open questions and bring us closer to understanding our fascinating star.

The research has been published.