If you’re an astronomy buff, you’ll already know that we had three big solar flares in the last two days. According to NASA, they were classified in Class X, the biggest ones of all. We happen to be in a peak year of an apparent 11-year cycle for these eruptions.
First have a look:
What is a solar flare? A separate NASA page tells us (my emphasis):
A flare is defined as a sudden, rapid, and intense variation in brightness. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. Radiation is emitted across virtually the entire electromagnetic spectrum, from radio waves at the longwavelength end, through optical emission to x-rays and gamma rays at the short wavelength end. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time! The first solar flare recorded in astronomical literature was on September 1, 1859. Two scientists, Richard C. Carrington and Richard Hodgson, were independently observing sunspots at the time, when they viewed a large flare in white light.
As the magnetic energy is being released, particles, including electrons, protons, and heavy nuclei, are heated and accelerated in the solar atmosphere. The energy released during a flare is typically on the order of 1027 ergs per second. Large flares can emit up to 1032 ergs of energy. This energy is ten million times greater than the energy released from a volcanic explosion. On the other hand, it is less than one-tenth of the total energy emitted by the Sun every second.
There are typically three stages to a solar flare. First is the precursor stage, where the release of magnetic energy is triggered. Soft x-ray emission is detected in this stage. In the second or impulsive stage, protons and electrons are accelerated to energies exceeding 1 MeV. During the impulsive stage, radio waves, hard x-rays, and gamma rays are emitted. The gradual build up and decay of soft x-rays can be detected in the third, decaystage. The duration of these stages can be as short as a few seconds or as long as an hour.
Two photos from NASA:
And more information about yesterday’s events:
On June 11, 2014, the sun erupted with its third X-class flare in two days. The flare was classified as an X1.0 and it peaked at 5:06 a.m. EDT. Images of the flare were captured by NASA’s Solar Dynamics Observatory. All three flares originated from an active region on the sun that recently rotated into view over the left limb of the sun.
To see how this event may affect Earth, please visit NOAA’s Space Weather Prediction Center at http://spaceweather.gov, the U.S. government’s official source for space weather forecasts, alerts, watches and warnings.
. . . This flare is classified as an X2.2 flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.