Thursday, September 20, 2012

AR 1576 C2 Flare on the 19th

The above image was taken September 19th at 15:12:00 UTC by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). The image is an actually a stacking of frames taken at multiple wavelengths. Specifically, 94, 131, 171, 193, and 211 Angstroms. These images were taken at the time of the C2 solar fare produced by Active Region 1576 (AR 1576) on the eastern (left) limb and to the south. The dark triangular shape just to the right of center is a coronal hole. Image Credit: SDO/AIA

For the end of September 18th and most of the 19th, the solar activity was low.  The new Active Region 1576 (AR 1576) produced a few C-class flares, the largest a C2/Sf on the 19th at 15:12 UTC. Both AR 1576 and AR 1575 continue to rotate onto the Earth-facing disc and appear to have beta magnetic characteristics.  No Earth-directed coronal mass ejections (CMEs) were detected. The forecast through September 22nd: The solar activity is expected to be at low levels with a slight chance for M-class activity.

At home, the geomagnetic field was at quiet to unsettled levels. The Advanced Composition Explorer (ACE) satellite measurements of the solar wind observed steady velocities at about 400 km/s while the Bz component of the interplanetary magnetic field varied between +8 to -10 nT. The forecast through September 22nd: The geomagnetic field is expected to remain at quiet to unsettled levels for the 20th. An increase to quiet to unsettled levels with isolated active intervals is expected for the 21st and 22nd as a coronal hole high-speed stream moves into a geoeffective position. 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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