A few months ago, a small, potentially inhabitable planet was discovered near our star next to us.
Proxima Centauri itself is a red dwarf; it is ten times lighter than the Sun and a thousand times dimmer. However, the new work revealed an unexpected similarity of two stars: like the Sun, it has regular cycles of activity, which are accompanied by fluctuations in the size and number of spots.
Sunspots are areas of low-temperature plasma output raised from the depths of a star by its powerful magnetic field. The cycle of its activity takes about 11 years, and during periods of minimum sunspots on a star may not exist at all, and at maximums their number may exceed a hundred, covering almost 1% of the Sun’s surface.
Judging by the data published in the journal of the Royal Astronomical Society, the Proxima Centauri is going through similar activity cycles. True, on this star these fluctuations are much more serious.
Using observational data at different wavelengths, as well as computer simulation results, Brad Wargelin and his colleagues from the United States and Poland showed that Proxima Centauri’s cycle of activity lasts about seven years and at the maximum is gaining awesome power: the spots cover at least 20 % of the surface of the star. “If there is intelligent life on the planet Proxima b, then its inhabitants regularly observe very dramatic changes on their star,” adds Brad Wargelin.
According to scientists, such bright cycles of activity in Proxima Centauri have become a big surprise for them. This red dwarf is arranged much differently than our yellow Sun, from which a whole third is occupied by the outer layer of rapidly moving and especially hot plasma, while the bowels are noticeably colder and calmer, and even rotate more slowly.
It is assumed that these differences are the source that triggers the cyclical changes in the activity of the star. At Proxima Centauri nothing like this should be: on a small star, all layers are mobile and capable of providing convection (energy transfer). “The very presence of Proxima Centauri’s cycles shows that we, in fact, have little understanding of how the magnetic fields of stars are born and how they generate cyclic activity,” explains Wargelin.
Scientists have not considered the question of how new circumstances may affect the possible habitability of the planet Proxima b. Theoretically, such a violent activity can completely sterilize its surface, so that the planet, being in a suitable “habitable zone”, can remain completely lifeless – like, for example, our Moon.