The Sun showed an unusual “smiling face“, and the curious moment was filmed by young amateur astronomers in Varna. On October 8, Viktoria Belcheva and Valentina Georgieva from the group at the National Astronomical Observatory and Planetarium “Nicolas Copernicus“ managed to photograph a configuration of sunspots that resembles a human face with a broad smile.
Behind the funny visual resemblance is actually one of the most interesting processes taking place on our star.
Sunspots are areas of the photosphere, the visible layer of the Sun, that are cooler than their surrounding environment. They appear in regions with extremely strong and complex magnetic fields that affect the movement of hot plasma and limit the transfer of heat to the surface.
It is the temperature difference that makes them appear dark in images of the Sun. However, this does not mean that the spots themselves are actually dark – if we could observe one of them in isolation, it would be extremely bright. The contrast with the much hotter surrounding photosphere creates their characteristic dark appearance.
To show the true scale of the observed phenomenon, the Varna Observatory superimposed images of the Earth and Jupiter on the photograph, taking into account their relative sizes to the Sun.
The comparison is impressive. The diameter of the Sun is approximately 1.39 million kilometers – about 109 times the diameter of the Earth. Its interior could theoretically accommodate about 1.3 million Earth-sized planets.
Sunspots can also reach enormous sizes. Individual groups extend for tens of thousands of kilometers, which means that some of them can be comparable in size to or even larger than our planet.
These areas are of particular interest to astronomers for another reason. The complex magnetic fields around active regions can be associated with solar flares and coronal mass ejections. When such phenomena are directed at Earth, they can cause geomagnetic storms and impressive auroras, and in stronger events - they can affect satellite communications, navigation systems and power transmission infrastructure.