The large red spot on Jupiter is the largest example of a long-lived storm in the solar system. But now the storm from Jupiter competes with a star from another system. And this is not a huge gas giant, but a cold little star, in the upper layers of which this storm was discovered.
L-dwarfs are a special kind of tiny stellar objects that have similar features with planets and stars at the same time. Known more colloquially as “failed stars”, brown dwarfs are too massive to be classified as planets, but too small to treat stars. Brown dwarfs form a bridge between the planets and the stars, and their weight may differ several times from the weight of Jupiter (although in size it is about the same as Jupiter). They are also called astronomical vagrants, as they possess features of both stars and planets at the same time, but they are not included in any of these groups.
For example, although some of the more massive brown dwarfs (such as M- and L-dwarfs) may have minor mergers (the star property) in the nuclei, this is not enough to raise the temperature of an object by a couple thousand degrees. Because of this, the atmosphere can stratify (split up, split up) and a phenomenon such as the appearance of clouds occurs (a property of the planet). But instead of clouds usually powerful storms appear on the surface of dwarfs. NASA's wide-angle infrared survey researcher discovered W1906 + 40 in 2011, and then astronauts realized that the object was always in sight of NASA thanks to the Kepler space telescope, which is designed to search for exoplanets. Usually Kepler is looking for a new exoplanet transit method, observing the orbit in front of the star. At the time of the passage of the planet against the background of a star, a small eclipse occurs, as the planet covers the star, and its luminosity and brightness decreases. But sometimes Kepler also detects “star spots” - basically these are huge dark spots with magnetic activity, located in the upper layers of the star.
Thus, using Kepler, and finding that the light of the star W1906 + 40 is very weak, astronomers also noticed a huge dark spot rotating with the L-dwarf. Could this be the appearance of another large dark star spot or a cluster of star spots, as in Sun during periods of high magnetic activity?
In order to investigate this phenomenon, scientists resorted to the help of another Spitzer space telescope. And what they found was a real surprise.
Looking at the brown dwarf in infrared light, Spitzer determined that the large black appearance on the W1906 + 40 surface was not at all due to magnetism and this was not a star spot. In fact, this is an atmospheric phenomenon. It turned out that it was a big dark storm near the north polar region. “The star is the size of Jupiter, and a storm the same size as the Great Red Spot on Jupiter,” says the author of a study published in the Astrophysical Journal, John Ghysis of the University of Delaware, Newark. “We know that the storm we discovered lasted at least two years, and possibly longer.”
He also added: “We do not know whether this type of star storm is unique or common, and also why it lasts so long.”
All this leads to the fact that, perhaps, the name “failed star” may be erroneous. Perhaps brown dwarfs should actually be known as “super-eruptive planets.”