MOSCOW, November 1. /TASS/. Scientists have registered a solar flare of the most powerful X-class in the early hours of Friday, Russia’s Fedorov Institute of Applied Geophysics has told TASS.

"On November 1, at around 12:17 a.m. Moscow time (9:17 p.m. GMT on Thursday), a 27-minute-long solar flare classified as X1.3 was recorded in X-rays in sunspot group 3878 (N17E29)," the scientists said in a statement.

Solar flares are divided into five classes according to their X-ray strength: the smallest ones are A-class, followed by B, C, M and X. A0.0 class is equal to the radiation energy found in the Earth’s orbit, 10 nanowatts per square meter. Each letter stands for a 10-fold increase in energy output. As a rule, the flares, known as giant explosions on the sun, send solar plasma into space, and the clouds of these charged particles can bring about geomagnetic storms when reaching the Earth.