Solar flares that reach or even surpass the X10 class are however very rare and occur only a few times during a solar cycle. So what’s above X9? The X-class continues after X9 instead of getting a new letter and these solar flares are often referred to as ‘’Super X-class’’ solar flares. Image: An X-class solar flare as seen by NASA’s Solar Dynamics Observatory in the 131 Ångström wavelength. If the solar flare is eruptive and takes place near the center of the Earth-facing solar disk, it could cause a strong and long lasting solar radiation storm and release a significant coronal mass ejection that can cause severe (G4) to extreme (G5) geomagnetic storming at Earth. Strong to extreme (R3 to R5) radio blackouts occur on the daylight side of the Earth during the solar flare. On average, solar flares of this magnitude occur about 10 times a year and are more common during solar maximum than solar minimum. X-class solar flares are the biggest and strongest of them all. If the solar flare takes place near the center of the Earth-facing solar disk and launches a coronal mass ejection towards our planet, there is a high probability that the resulting geomagnetic storm is going to be strong enough for aurora on the middle latitudes. Strong, long duration M-class solar flares are likely candidates to launch a coronal mass ejection. Some eruptive M-class solar flares can also cause solar radiation storms. They cause small (R1) to moderate (R2) radio blackouts on the daylight side of the Earth. M-class solar flares are what we call the medium large solar flares. The background flux (amount of radiation emitted when there are no flares) can be in the lower C-class range when a complex sunspot region inhabits the Earth-facing solar disk. Only C-class solar flares which are long in duration might produce a produce a coronal mass ejection but they are usually slow, weak and rarely cause a significant geomagnetic disturbance here on Earth. C-class solar flaresĬ-class solar flares are minor solar flares that have little to no effect on Earth. The background flux (amount of radiation emitted when there are no flares) is often in the B-range during solar maximum and in the A-range during solar minimum. They are very common and not very interesting. The A & B-class are the lowest class of solar flares. Solar flares of X10 or stronger are sometimes also called “Super X-class solar flares.” A & B-class solar flares The X-class class category is slightly different and doesn’t stop at X9 but continues on.
An X2 flare is twice as powerful as an X1 flare, and is four times more powerful than an M5 flare.
The table below shows us the different solar flare classes: ClassĮach X-ray class category is divided into a logarithmic scale from 1 to 9. Solar flares are classified as A, B, C, M or X according to the peak flux (in watts per square metre, W/m 2) of 1 to 8 Ångströms X-rays near Earth, as measured by XRS instrument on-board the GOES-15 satellite which is in a geostationary orbit over the Pacific Ocean. Image: A spectacular solar flare as seen by the NASA’s Solar Dynamics Observatory in the 193 Ångström wavelength. When a coronal mass ejection arrives at Earth, it can cause a geomagnetic storm and intense auroral displays. Some (mostly stronger) solar flares can launch huge clouds of solar plasma into space which we call a coronal mass ejection. Large flares are less frequent than smaller ones. Many solar flares can occur on just one day during this period! Around solar minimum, solar flares might occur less than once per week. The amount of energy released is equivalent to millions of nuclear bombs exploding all at the same time! Solar flares are an often occurrence when the Sun is active in the years around solar maximum. Material is heated to many millions of degrees in just minutes and radiation is emitted across virtually the entire electromagnetic spectrum, from radio waves at the long wavelength end, through optical emission to X-rays and gamma rays at the short wavelength end. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. A solar flare is defined as a sudden, rapid, and intense variation in brightness. A solar flare is basically a giant explosion on the surface of our Sun which occurs when magnetic field lines from sunspots tangle and erupt.