Astronomers first saw superflare on ultracold white dwarf

White dwarfs are relatively cold, dim remnants of stellar bodies, such as our Sun. When

stars are running out of nuclear fuel sheswells and turns into a huge red giant, and then discards the outer layers. When this process is completed, only a small superdense core remains from the star, which astronomers call a white dwarf.

L-type dwarfs are even colder than usual - temperatureon their surface it is estimated at 1,300–2,300 K, and the mass is in the range between the stellar and the mass of brown dwarfs. Such objects may have flare activity, however, as previously thought, they are not able to generate powerful flashes.

Researchers Observing WhiteDwarf J0331−27, located at a distance of about 240 pc from the Sun, noticed a superflare on it. Its decay time was about 2.4 thousand seconds - for this, 2 × 10 to 34 degrees of energy was released.

The authors of the study note that during thisIn a very short time, the star released tens of times more energy than during the most powerful solar flares, which last much longer.

While scientists cannot say why this phenomenon occurs, registration of superflares on other L-dwarfs will allow to answer this question.

Earlier astronomers for the first time discovered evidence of the existence of a large planet onorbit a white dwarf. A study of the white dwarf WD J0914 + 1914 showed that the star is surrounded by a gas disk, which includes substances characteristic of ice giants.