April 19, 2024

A Guide to Solar Flares: What Does It Take To Be X-Class?

Solar flares are giant explosions on the sun that send out energy, light, and high speed particles into area. The number of solar flares increases around every 11 years, and the sun is presently moving towards another solar maximum, most likely in 2013. The greatest flares are understood as “X-class flares” based on a classification system that divides solar flares according to their strength. X is the last letter, there are flares more than 10 times the power of an X1, so X-class flares can go greater than 9. The biggest X-class flares are by far the biggest surges in the solar system and are awesome to watch.

Solar flares are giant surges on the sun that send energy, light, and high speed particles into area. The number of solar flares increases roughly every 11 years, and the sun is currently moving towards another solar optimum, likely in 2013.
The most significant flares are known as “X-class flares” based on a classification system that divides solar flares according to their strength. The tiniest ones are A-class (near background levels), followed by B, C, M and X. Similar to the Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. So an X is 10 times an M and 100 times a C. Within each letter class there is a finer scale from 1 to 9.

Solar flares are categorized according to their strength. The smallest ones are A-class, followed by B, M, c and x, the biggest.
C-class and smaller flares are too weak to significantly impact Earth. M-class flares can trigger short radio blackouts at the poles and minor radiation storms that may endanger astronauts.
An X-class solar flare (X9.3) discharged on September 6, 2017, and caught by NASAs Solar Dynamics Observatory in severe ultraviolet light. Credit: NASA/GSFC/SDO
And after that come the X-class flares. X is the last letter, there are flares more than 10 times the power of an X1, so X-class flares can go higher than 9. The most powerful flare measured with modern-day methods remained in 2003, throughout the last solar maximum, and it was so powerful that it strained the sensing units measuring it. The sensors eliminated at X28.
The Solar and Heliospheric Observatory (SOHO) spacecraft recorded this image of a solar flare as it appeared from the sun early on Tuesday, October 28, 2003. Credit: ESA & & NASA/SOHO
The greatest X-class flares are by far the largest explosions in the solar system and are remarkable to view. When the suns magnetic fields cross over each other and reconnect, loops 10s of times the size of Earth leap up off the suns surface area. In the most significant occasions, this reconnection process can produce as much energy as a billion hydrogen bombs.
If theyre directed at Earth, such flares and associated CMEs can produce long lasting radiation storms that can hurt satellites, communications systems, and even ground-based innovations and power grids. X-class flares on December 5 and December 6, 2006, for example, triggered a CME that disrupted GPS signals being sent out to ground-based receivers.
The Halloween solar storms of 2003 resulted in this aurora visible in Mt. Airy, Maryland. Credit: NASA/George Varros
NASA and NOAA– in addition to the US Air Force Weather Agency (AFWA) and others– keep a constant watch on the sun to keep an eye on for X-class flares and their associated magnetic storms. With advance alerting many satellites and spacecraft can be secured from the worst effects.

By Karen C. Fox, NASAs Goddard Space Flight
November 4, 2021