Sunday, September 16, 2012

Large Prominence Beyond the Western Limb...

The above image was taken September 15th at 16:52:00 UTC by the Atmospheric Imaging Assembly (AIA), at 304 Angstroms, aboard the Solar Dynamics Observatory (SDO). This was during the time of the a large prominence beyond the western limb. Image Credit: SDO/AIA

For the end of September 14th and most of the 15th, the solar activity was very low. Low-level B-class x-ray flares occurred. Active Region 1566 (AR 1566) produced occasional B-class flares as it approached the sun's west limb. Occasional B-class flares also occurred from a yet-to-be-numbered small spot group that rotated into view late in the period. AR 1569 showed minor spot growth in its trailer portion and retained a beta-gamma magnetic configuration. And a new region was designated, AR 1572. One very spectacular event for the period was a large prominence which extended from beyond the sun's western limb, occurring on the 15th around 16:52 UTC. That being said, there were no Earth-directed coronal mass ejections (CMEs) observed. The forecast through September 18th: The solar activity is expected to be very low with a chance for isolated C-class flares.

Above Earth, the geomagnetic field ranged from quiet to (briefly) unsettled levels. The forecast through September 18th: The geomagnetic field activity is expected to increase to unsettled levels around midday on the 16th with a chance for active levels due to the arrival of the CME associated with the filament disappearance observed on the 13th. Field activity is expected to decrease to quiet to unsettled levels on the 17th as CME effects subside. A further decrease to quiet levels is expected on the 18th. Stay tuned...

To monitor solar flare activity minute by minute, visit the "Today's Space Weather" page of NOAA's Space Weather Prediction Center (

To learn more about the sun and to stay current on solar activity, visit the mission home pages of the Solar Dynamics Observatory (SDO) (, the Solar and Heliospheric Observatory (SOHO) (, the Advanced Composition Explorer (ACE) (, and the Solar Terrestrial Relations Observatory (STEREO) (


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