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Sun Sends Out Mid-Level Solar Flare
The sun emitted an M7.7 class solar flare on July 19, 2012. This video, taken by the Solar Dynamics Observatory (SDO), shows the flare in 304 and 335 wavelengths. Credit: NASA/SDO

A coronal mass ejection (CME) was also associated with the July 19, 2012 flare. A CME is another solar phenomenon that can send solar particles into space and can reach Earth one to three days later, affecting electronic systems in satellites and on the ground. Initial NASA research models show that this CME is not headed toward Earth, but could impact STEREO-A.

NOAA's Space Weather Prediction Center ( is the United States Government official source for space weather forecasts and alerts. Space Weather Prediction Center reports "Region 1520, now past the west limb, continues to erupt. It produced an R2 (moderate) Radio Blackout and a CME earlier today. Although not clearly Earth-directed, forecasters are analyzing it for tangential effects on the geomagnetic field. An S1 (minor) Solar Radiation Storm soon followed the eruption."

More information on different types of space weather including Solar Radiation Storms and Radio Blackouts:

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Image captured by SDO on July 19, 2012 of M7.7 class solar flare. › View larger
This image was captured by NASA's Solar Dynamics Observatory (SDO) on July 19, 2012 of an M7.7 class solar flare. The image represents light in the 131 Angstrom wavelength, which is particularly good for seeing flares, and which is typically colorized in teal. Credit: NASA/SDO

The sun emitted a mid-level solar flare on July 19, 2012, beginning at 1:13 AM EDT and peaking at 1:58 AM. Solar flares are gigantic bursts of radiation that cannot pass through Earth's atmosphere to harm humans on the ground, however, when strong enough, they can disrupt the atmosphere and degrade GPS and communications signals.

The flare is classified as an M7.7 flare. This means it is weaker than the largest flares, which are classified as X-class. M-class flares can cause brief radio communications blackouts at the poles.

Increased numbers of flares are currently quite common, since the sun's standard 11-year activity cycle is ramping up toward solar maximum, which is expected in 2013. It is quite normal for there to be many flares a day during the sun’s peak activity.

Updates will be provided as they are available on the flare and whether there was an associated Earth-directed coronal mass ejection (CME), another solar phenomenon that can send solar particles into space and affect electronic systems in satellites and on Earth.

What is a solar flare? What is a coronal mass ejection?

For answers to these and other space weather questions, please visit the Spaceweather Frequently Asked Questions page.

Related Link
› View Past Solar Eruptions
Karen C. Fox
NASA Goddard Space Flight Center, Greenbelt, MD