12 December


Solar activity was low. Region 1916 (S13W85, Hax/alpha) began the period
as the most active spot group, producing a couple of C1 flares. Region
1917 (S15E12, Dao/beta-gamma) then produced a C2/Sf flare at 11/2306
UTC, as well as a long duration C3 flare at 12/0659 UTC. Region 1912
(S21W55, Hax/alpha) decided to finish out the period on an active note,
producing a C4/Sf flare at 12/0336 UTC. A type-II radio sweep estimated
at 511 km/s and a type-IV radio sweep were also observed in conjunction
with this event, as well as several discreet radio bursts at different
frequencies.

There was a 15 degree filament, centered near S31W41, that was observed
in SDO/AIA 304 imagery lifting off the solar disk from 12/0304 UTC to
12/0330 UTC. The resulting partial halo coronal mass ejection (CME) can
first be seen in Lasco C3 imagery at 12/0618 UTC. But, with a large data
gap, the CME appears to have already traveled well away from the solar
disk by the time the first image appears. A current Enlil model run has
been submitted, using the limited data available, and results will be
analyzed to determine if there is a Earthward component to the CME.

A second CME was observed in LASCO C2 imagery at 12/0636 UTC departing
the solar disk with a southerly trajectory. This CME is associated with
a 7 degree filament that departed the solar disk from 12/0451 UTC to
12/0624 UTC and was centered near S32E27. An additional Enlil run may be
accomplished as more data becomes available, though initial analysis
indicates the ejecta was directed too far southward to have any major
impacts on the Earth.

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