Significant X-Class Solar Flare Causes Radio Blackout, CME

A significant X-class solar flare unfurled from the Sun early Tuesday morning, causing a strong radio blackout and an associated coronal mass ejection (CME).

The X1.0 grade flare peaked at 5:26 a.m. EST on Nov. 19, originating from an active sunspot region known as AR 1893. The sunspot is not directly facing Earth and is beginning to rotate out of sight over the Sun's right side, according to NASA.

The associated CME was not Earth-directed and no geomagnetic storms are expected. Click here to see a video of the CME. 

Tuesday's flare adds to a series of notable solar activity that has taken place throughout October and November. In October there were 28 recorded solar flares, including thee X-class flares, and the strongest flare of the year was among November's solar events. 

Solar fares are powerful bursts of radiation. Although they cannot pass through the Earth's atmosphere and harm humans on the ground, the radiation can disturb GPS systems and other radio equipment.

SpaceWeather.com reported that the flare produced a "wave of ionization" in the upper atmosphere over Europe, Africa and Asia.

The flare generated a 10cm radio burst that lasted for seven minutes, according to NASA's Space Weather Prediction Center.

"A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications," the agency wrote online.

November has seen a number of notable solar flares, including the most powerful one of the year. The X3.3-grade flare peaked the evening of Nov. 5 and caused a a wide-area blackout of high frequency signals for about an hour.

The Nov. 5 solar flare surpassed an X3.2 event in May, although both events were orders of magnitude less powerful than the strongest flare of this 11-year solar cycle, an X6.9 which took place in August 2011.

There are several classes of solar flares, but M-class and X-class are most noteworthy because they can cause geomagnetic storms on Earth. M-class flares are the weakest type of solar flare that can cause some space weather effects near Earth, while X-class flares are the most powerful class of solar flare.

The numbers following the flare's letter class provide more information about the flare's strength. An X2 flare, for instance, is twice as strong as an X1.