Solar activity summary (Last 24 hours)

27 December


Solar activity remained at low levels. Region 1934 (S16W19,
Cao/beta-gamma) produced two of the three C-class flares during the
period. The first, a C1/Sf, erupted at 27/0938 UTC with the second, a C2
flare, occurring at 27/1122 UTC. Both appeared to originate from the
area near the trailer spots. Region 1936 (S16E25, Dai/beta-gamma)
produced the only other flare of the period, a C1/Sf, that erupted at
27/0734 UTC. Neither appeared to produce associated coronal mass
ejections (CMEs). Region 1931 displayed slight penumbral separation, but
remained stable as it progressed to the west limb. Region 1934
maintained a weak mix of polarities in its trailer portion, but was also
fairly stable throughout the period. Region 1936 also maintained a weak
mix of polarities in its trailer portion, showed spot and penumbral
development early in the period, then developed another spot in the
leader. This region is the spot group of interest and should be
monitored closely. New Region 1938 (S13E68, Hax/alpha) was numbered as a
simple H-type group as it rotated further onto the visible disk over
night. There were no Earth-directed CMEs detected during the period.

26 December


Solar activity was low. Regions 1931, (S16W22, Hax/alpha), 1934 (S15E07,
Eao/beta-gamma), 1936 (S16E36, Eai/beta-gamma), and old Region 1928
(S14, L=008) all produced isolated low-level C-class flares.
Region 1931 produced the largest of these flares, a C2/Sf, at 26/0702
UTC. This region exhibited minor development in the leader spots while
decreasing in areal coverage. Region 1936 displayed growth in the
trailer spots and more than doubled in areal coverage to 110 millionths.
This region also retained a beta-gamma magnetic structure with weak
mixed-polarity fields in the vicinity of its trailer spots, along with
minor spot decay noted in its intermediate portion. The remaining four
spot groups were unremarkable. New Region 1937 (S12E65, Cso/beta) was
numbered over night as it rotated into view. A full halo coronal mass
ejection (CME) was observed in STEREO B imagery at 26/0410 UTC. This
CME was attributed to a back-sided event with no impact to Earth
expected. There were no Earth-directed CMEs detected during the period.

25 December


Solar activity was low. Region 1928 (S16, L=08) did not rotate off the
visible disk quietly. It was responsible for several low level C-class
flares as well as the largest flare of the period, a C4 flare, that
occurred at 25/0639 UTC. Region 1936 (S17E48, Eai/beta-gamma) also
produced low-level B- and C-class flares throughout the period. Regions
1934 (S14E07, Eai/beta-gamma) and 1936 both contained a beta-gamma
magnetic configuration, exhibited growth in overall length, and will be
the spot groups of interest in the following days. The remaining spot
groups were either stable or showed signs of slight decay. No new
regions were numbered and there were no Earth-directed coronal mass
ejections observed during the period.

24 December


Solar activity returned to low levels over the past 24 hours. The
largest event of the period, a C8/Sf flare, was produced by Region 1936
(S15E60, Cao/beta) as it rotated on to the visible disk. Region 1928
(S16W76, Dai/beta-gamma) was the most active region, producing several
C-class flares throughout the period, but showed signs of decay as it
neared the west limb. All of the other spot groups were either stable or
exhibited signs of decay. An eruptive prominence on the eastern limb was
observed in SDO/AIA 304 imagery from approximately 24/0943 UTC to
24/1015 UTC. Initial analysis indicates the associated coronal mass
ejection (CME) has a southward trajectory and should not have an impact
on Earth. There were no Earth-directed CMEs detected during the period.

23 December


Solar activity was high due to a total of five M-class flares observed
throughout the period. The largest event, an M3 flare, was observed at
22/1512 UTC from Region 1928 (S16W67, Ekc/beta-gamma). In addition,
Region 1928 produced an M1/Sn flare at 22/2208 UTC, an M1/Sf flare at
23/0003 UTC, and an M1/1n flare at 23/0906 UTC. Region 1934 (S16E32,
Dao/beta-gamma) produced an M1/1n flare at 22/1438 UTC. Regions 1928
and 1934 appeared to grow slightly in the past 24 hours while the other
regions were either stable or undergoing minor decay. A 24-degree
eruptive prominence centered near N32W90 was observed in GONG H-Alpha
imagery between 23/0807 – 0832 UTC. No Earth-directed coronal mass
ejections (CMEs) were observed.

22 December


Solar activity was moderate. Region 1928 (S18W55, Ekc/beta-gamma)
produced a pair of M1/Sf flares at 22/0811 UTC and 22/0837 UTC, which
were the largest events of the period. Region 1928 remains the largest
and most productive region on the disk. Region 1934 (S15E45,
Dac/beta-gamma) appeared to grow in both size and magnetic complexity
this period and was responsible for a C6/1f flare 22/0932 UTC. The
other regions on the visible disk were stable or in decay. No
Earth-directed coronal mass ejections (CMEs) were observed.

21 December


Solar activity was low. Region 1928 (S17W41, Ekc/beta-gamma) produced a
C9/1f flare at 21/1036 UTC, which was the largest event of the period.
Region 1928 remains the largest and most magnetically complex region on
the disk and exhibited minor growth and evolution throughout the period,
especially in its intermediate spot area. Region 1934 (S15E58,
Dao/beta) also exhibited growth this period, but did not produce any
reportable events. The other regions on the visible disk were either
stable or in decay. A 20-degree filament eruption on the eastern limb
(S20E90) was observed between 21/0345 – 0431 UTC in GONG H-Alpha
imagery. No Earth-directed coronal mass ejections (CMEs) were observed
this period.

20 December


Solar activity was at moderate levels. Newly-numbered Region 1934
(S15E71, Csi/beta) produced an M3 flare at 19/2319 UTC and an M1 flare
at 20/1157 UTC, which were the largest events of the period. Due to its
proximity to the limb, Region 1934 likely contains additional structure
that has yet to rotate into view. Newly-numbered Region 1933 (S12W45,
Dai/beta) developed rapidly this period, but has remained unproductive
thus far. Region 1928 (S16W26, Ekc/beta-gamma) exhibited minor growth
and evolution throughout the period and remains the most magnetically
complex and largest region on the visible disk. The other regions on
the disk were either stable or undergoing minor decay. A 7-degree
filament eruption centered near N24W57 was observed in GONG H-Alpha
imagery between 20/0651 – 0821 UTC, but appeared to be mostly
reabsorbed. No Earth-directed coronal mass ejections (CMEs) were
observed this period.

19 December


Solar activity was low. Region 1930 (S10E29, Dai/beta) was the most
active spot group, producing three C-class flares during the period.
Each event was C1 in magnitude with the flare at 19/0719 UTC having a
subfaint optical correlation. This region continues to be in a growth
phase, showing separation between the leader and trailer spots, as well
as development in the intermediate spots. Region 1928 (S16W12,
Ekc/Beta-Gamma) also continued to develop, showing consolidation in the
leader spots, consolidation in the intermediate spots, yet overall
separation between the leader and trailer spots. This region also
produced a C1/Sf flare at 19/0918 UTC. The other regions on the visible
disk were either stable or exhibited signs of decay. No Earth-directed
coronal mass ejections were detected in satellite imagery throughout the
period.

18 December


Solar activity was low. The largest event of the period was a C4 flare
that occurred at 17/2329 UTC. This flare appeared to originate from a
region beyond the east limb, likely old Region 1913 (S14, L=268). Region
1917 (S16W70, Dai/beta-gamma) was the most active region of the period,
producing several low level C-class flares. Region 1928 (S15E02,
Dki/beta-gamma) continued to exhibit areal growth as well as penumbral
separation and magnetic mixing. Region 1929 (S12E61, Hsx/alpha) was
numbered over night as a simple Hsx spot group. The other regions on the
disk were either stable or indicated minor decay. No Earth-directed CMEs
were detected in imagery.