Each month a summary of sunspot activity is written and forms part of a report sent to the Solar Section of the British Astronomical Association (BAA) and to The Astronomer. Follow the links below to read a page summary of sunspot activity. The McIntosh Sunspot Group Classification is used for sunspot group descriptions.

January 2012

The largest of the five groups seen on the 2nd was AR 1389 at 19°S/84° – this was of type Ekc with an area of 350 millionths. It consisted of a slightly asymmetrical leading penumbral sunspot and a collection of smaller following sunspots.  All of the followers had disappeared by the 6th to leave an Hkx sunspot. Close to the eastern limb on the 2nd was an Hsx sunspot (AR 1391) – by the 6th it was seen as a Dkc group at 11°N/11° where the leading sunspot contained most of the area of the group of 320 millionths. When next seen on the 11th AR 1391 was much smaller at 170 millionths despite the group becoming type Eac. Between the 6th and 11th AR 1393 at 19°N/52° changed from type Bxo to a Eac group near the western limb. On the 13th and 14th AR 1391 continued to decay to become type Dso when last seen on the limb on the 14th.

Two of the 9 groups seen on the 15th were close to the eastern limb: AR 1401 and AR 1402.  AR 1401 was first seen as type Hsx on the 14th before becoming type Cso on the 15th and then type Eac on the 16th at 17°N/214°.  By the 19th it was seen approaching the central meridian when it has an area of 420 millionths – it consisted as a string of three cluster of almost equally sized penumbral sunspots. Further development had taken placed by the 21st when the main sunspot was towards the middle of the group. AR 1402 some 10° to the north of AR 1401 was a Hax sunspot when first seen on the 15th and type Hkx on the 16th. By the 19th it was seen as Dko at 30°N/211° with an area of 370 millionths: it consisted of a small leading penumbral sunspot with a much larger irregular follower. This follower had changed shape slightly by the 21st and the total area was almost unchanged. AR 1402 was last seen on the western limb as on 27th. The last observation of the month on the 28th showed just three small groups.

Hydrogen Alpha:

February 2012

Two of the four northern groups from the 1st were AR 1413 and AR 1410. AR 1413 at 9°N/6° was a small Dao group with an area of 40 millionths – it grew in size over the next two days to 130 millionths but it had lost most of its pore sunspots. Just to its north was AR 1410 at 18°N/58° of type Hax with an area of 150 millionths – it became type Cao on the 2nd before reverting to type Hsx on the 3rd. It was last seen on the 7th close to western limb but now of type Dso (indeed it was the only group seen on the date).

The next observation on the 11th showed just two groups. AR 1416 at 18°S/287° was of type Dkc with an area of 320 millionths which consisted of a bipolar group where the largest penumbral sunspot was the following one and with several small sunspots within the group. AR 1417 at 16°N/239° was of type Hsx with an area of 50 millionths.

All of the five groups seen on the 19th were small – the largest was AR 1422 at 18°N/177° of type Dac and an area of 80 millionths. By the 21st it grew to 320 millionths where the leader was quite elongated and the largest sunspot in the group. This group reduced in size slightly by the 23rd and was last seen near the limb as a Hax sunspot on the 25th. The last observation of the month on the 26th showed four small groups in the north east quadrant of the Sun.

Hydrogen Alpha:

On the 11th filaments were the dominant Hα feature with a long string of filaments in the NW quadrant as well as near the South Pole. A similar number of filaments were seen on the 19th but these were quite short and spread throughout the disk. A moderately tall prominence was seen on the NE limb and plage was visible around AR 1422.  The same flame and spike prominence was seen on the SW limb and SE limb respectively on the 25th and 26th. Filaments were seen on both dates including a string a filaments spanning the meridian in the southern hemisphere. Plage was still seen around AR 1422 but only on the 25th having rotated off the disk on the 26th.

March 2012

A medium sized Hkx sunspot was seen close to the eastern limb on the 3rd at 17°N/299°.  By the 6th this group, AR 1429 was now seen as an irregular and elongated penumbral sunspot with many umbra and a small region of photosphere within it. A smaller penumbral sunspot was also seen towards the north east of the main sunspot – its total area was estimated to be 700 millionths. When next seen on the 8th it was close to the central meridian and slightly larger at 920 millionths – again many umbra were seen. By the 11th several penumbral sunspots were seen due to the splitting of the main penumbral sunspot - the total area was a reduced 500 millionths and it was of type Ekc. A single Hsx sunspot on the western limb was all that remained of AR 1429 on the 15th (the leading part of the group may have already rotated off the disk).   On the 6th a small Csi group, AR 1430, was seen some 15° to the west of AR 1429 at 19°N/315°. By the 8th the penumbral sunspot has become asymmetric to give a Cai group with an area of 160 millionths. It had decayed to type Cso when last seen on the 11th.  During this period the other notable group was in the southern hemisphere was AR 1428 at 16°S/319° which had a maximum area of 170 millionths on the 8th when the group was bipolar and of type Dao.

From the 15th onwards all the groups seen were small – the largest being an Esc group at 23°S/25° on the 26th (AR 1445).  From the 20th onwards, and unusually for this solar cycle, there were more groups in the southern hemisphere than in the northern hemisphere. For example on the 28th there were five southern groups and one northern group.

Hydrogen Alpha:

On the 3rd several small prominences were seen together with a dark filament in the NE and plage around AR 1423. On the 11th a tall spike like prominence was seen on the SE limb while on the disk the majority of Hα activity was confined to the northern hemisphere with a long multi part filament in the NE quadrant. Plage was also seen around AR 1429, AR 1430 and AR 1432. Very little activity was seen on the 24th which improved slightly by the following day with plage being seen around AR 1440 and AR 1444. An active multiple arch prominence was seen on the NE limb on the 26th with an estimated height of 100,000 km. A few filaments were seen on the disk as well as plage AR 1444.

April 2012

White light activity was quite low during the first half of the month before becoming moderately high for the third week before reducing slightly towards the month’s end. On the 1st four groups were seen where the largest was AR 1445 of type Hax at 21°S/31° with an area of 140 millionths. Another group, AR 1450 at 16°N/323°, was of type Bxo on the 1st before developing into type Csi on the 2nd and then into a small Eao group on the 4th having just passed the central meridian and then into a slightly larger Dai group on the 6th when it had an area of 150 millionths. This and AR 1452 were the only groups seen on the 6th.  Even lower activity was seen on the 11th when there were only two Axx groups (AR 1455 and AR 1454). AR 1455 at 6°N/206° was of type Dao on the 13th and 14th with an area of 130 millionths – it had decayed when last seen approaching the western limb on the 16th now of type Csi.

There was quite a contract in activity on the next observation on the 20th – there were now seven groups with several being moderately sized. The groups were also spit between the hemispheres, three in the north and four in the south.  Although AR 1459 at 14°S/91° was seen close to the eastern limb on the 16th it just comprised of four small penumbral sunspots; it now consisted of a small clump of many small penumbral and other sunspots. Two other southern groups had formed on the disk towards the west of AR 1459 – these were AR 1463 and AR 1462.  The main northern group on the 20th was the Dac AR 1460 at 16°N/108° and near the central meridian which comprised a string of moderately size penumbral sunspots. By the 21st AR 1459 had become type Eac and where the size of the many penumbral sunspots had increased slightly. AR 1462 was still of type Dao but it had increased in size to 450 millionths.  When seen on the following day AR 1459 has lost some if its penumbral sunspots but the leader had increased so that the group was now of type Ekc with an area of 350 millionths. AR 1462 was now approaching the western limb while the northern AR 1460 was of type Dao with an area of 320 millionths. The five groups from the 22nd were of a similar appearance by the following day.

On the 27th the largest of the five groups seen was AR 1466, a Fac group at 12°N/35° which had an area of 160 millionths. By the 29th AR 1471 of type Cho had rotated around the eastern limb and when seen on the following day it became type Eho – it had a total area of 360 millionths due mainly to the moderately sized leading sunspot.

Hydrogen Alpha:

Activity was quite low on the 1st with just a few small prominences but quite a few small filaments. On the following day a small arch prominence was seen on the NW limb while a moderately long filament was seen to the north of AR 1452 in the NE quadrant where two small regions of plage were seen.  The arch prominence was still visible on the 4th as was the filament which now appeared longer as it approached the central meridian. The plage region was also still visible.  The same long filament was seen on the 6th as was the plage – on this date all prominences were still small but there were still several other filaments visible. 

Hα activity had increased by mid-month as the height of prominence and the number of filaments had increased slightly. Plage was seen around AR 1455 and AR 1457 on the 13th and around AR 1455 and AR 1459 on the 16th. A bush type prominence was seen on the SE limb while slightly taller flame type prominences were seen on the SW limb, both on the 16th. On the same day another long filament was seen spanning the central meridian in the northern hemisphere.

May 2012

Activity during the month was dominated by one group – AR 1476.  The first observation of the month on the 7th showed AR 1476 near the eastern limb at 11°N/181° and of type Fkc: the largest sunspot was the leader which was quite irregular in shape and this was followed by a number of smaller penumbral sunspots. When next seen on the 11th AR 1476 was near the central meridian and the leader dominated the group and it had become quite irregular with many umbrae within it. A string of small penumbral sunspots had formed to the NE of the main sunspot. The group had an estimated area of 960 millionths. By the following day the leading sunspot had reduced in size but it now included two area of photosphere within it. There were some smaller penumbral sunspots to the west and south of this sunspot – the number of sunspots in the following string had reduced in number such that now the total area was 660 millionths. The group had decayed slightly when seen on the 13th but it was still of type Fkc. It was last seen on the 16th near the western limb as a single Hsx sunspot.  AR 1476 was seen with the protected naked eye on the 11th, 12th and 13th.

Together with AR 1476 on the 16th, six other groups were seen but none were particularly large. For the rest of the month there were either four or five groups seen for each observation – the largest being AR 1492 at 230 millionths when seen on the 27th at 12°S/283° and type Eao.

Hydrogen Alpha:

June 2012

Although 7 groups were seen on the first observation on the month on the 4th, none were particularly large – there largest were AR 1497 at 20°S/223° of type Dac and AR 1493 at 15°N/208° of type Eac each with an estimated area of 150 millionths.  There were an almost equal number of groups in the northern and southern hemispheres. The largest group of the month was first seen on the 9th as a Dsc group near the eastern limb at 15°S/85° (AR 1504). It was of a similar appearance on the following day but by the 13th it had developed into a bipolar group where the main sunspots were the leader and follower with an arc of smaller sunspots between.  It was now of type Ekc with a total area of 450 millionths. On the 14th some of the smaller sunspots had developed into a penumbral sunspot.  When next seen on the 16th, there were now three penumbral sunspots where the leader and followers were of almost equal size while the other sunspot to the north of the follower – the total area was now 610 millionths.  It was of a similar size on the 17th although it had become type Eac.  By the 19th, with the group nearing the western limb it had reduced to 430 millionths and it was finally seen on the 20th as a Dac group.  It was also the only group seen on the 20th and it was seen with the protected naked eye on the 13th, 14th and 16th.

 Activity on the 23rd, 24th and 25th was limited to one different group per day (AR 1511, 1510 and 1512 respectively).  On the 26th AR 1512, a Dsc group at 15°S/262° was joined by AR 1513 at 12°N/213° on the eastern limb as an Hsx sunspot.  Other groups has appear by the 29th and 30th (five on each day) where the largest was AR 1515 at 16°S/206° of type Dac and area 330 millionths on the 30th.  

Hydrogen Alpha:

July 2012

Activity was dominated by three moderately sized groups, all in the southern hemisphere. 

The first of these was AR 1515 which developed from a D type group at the end of June into an Eac group at 16°S/206° with an area of 450 millionths when seen on the 1st.  It was a particularly complex group with an asymmetrical leader and a set of complex following penumbral spots.  This group still retained its complex form when next seen on the 7th when it had an area of 690 millionths – now the largest sunspot was the follower.  This group was last seen on the 8th when it was close to the western limb. 

The second group, AR 1520, was seen close to the eastern limb on the 7th.  On the following day, this group at 16°S/86°, was of type Fkc with an area of 1190 millionths – the largest penumbral sunspot was near the centre with thin following extension and other surrounding sunspots.  Several umbrae were seen within the main sunspot as well as a region of photosphere.  This group was of a similar size when next seen a few days later on the 14th. The largest sunspot was now toward the following part of the group but there were still other penumbral sunspot leading and following the main sunspot. The appearance of the main sunspot changed appearance by the following day and it the total area of the group was slightly smaller at 1000 millionths.  AR 1520 was last seen close to the western limb on the 17th when it was still of type Fkc.  It was seen with the protected naked eye on the 13th and 14th.

The final moderately sized group, AR 1532, was initially seen as a single Hsx sunspot on the eastern limb on the 26th.  By the 28th, further following sunspots had rotated on to the disk to make the group, at 21°S/177°, of type Fko. By the 29th a penumbral sunspot had appeared between the leader and follower to make the group of type Fkc while by the 30th the irregularly shaped leader in increased to give the group a total size of 620 millionths.  

Hydrogen Alpha:

August 2012

Overall activity was high at the start of the month before reducing towards the middle of the month and then becoming high again at the month’s end.  Also activity was slightly higher in the southern hemisphere. None of the groups seen during the month were particularly large.

The Fkc group AR 1532 at 21°S/176° from July was seen straddling the central meridian on the 1st but with a reduced size of 320 millionths – the leader was still the largest sunspot in the group.  AR 1532 was also the largest of the seven groups seen on the 1st. On the 2nd AR 1532 has become type Fac through a further reducing in the size of the leader.  It was of similar appearance on the 3rd before on the 4th all but one of the following sunspots remained to make the group type Cao.  This group was last seen on the 5th as it neared the western limb.  On the 3rd and 4th ten groups were seen with a sunspot number of just over 120.

On the 8th a Dho group was seen close to the eastern limb at 20°N/20° - AR 1543. It was of the same type on the 9th before the leader became asymmetric to make the Dko when seen on the 10th. Several other sunspots were seen within the group on the 12th while on the 14th the group, now just past the central meridian, was of type Hkx with an area of 320 millionths.  Only two groups were seen on the 14th, the lowest number during the month.  AR 1543 was seen of type Hax on the 17th and 18th before being seen as type Dao as it approached the western limb on the 19th.

Observations on the 23rd and 25th to 28th showed either four or five small groups. Although the number of groups had increased by the 31st, the largest of the eight groups were AR 1553 at 20°S/182° of type Dac at 200 millionths and AR 1560 at 4°N/127° also of type Dac at 180 millionths.

Hydrogen Alpha:

An unusual prominence seen from 11 observations was on the 27th and 28th – on the 27th an almost rectangular block of hydrogen was seen on the NE limb.  The top of the prominence was quite flat and parallel to the limb; there was also a slight extension from the middle of the northern side of the prominence.  On the 28th, this extension could be seen extending onto the limb as a short filament. Also on this date, the height of the prominence had reduced slightly.

Many filaments were seen at the start of the month, especially on the 1st and 2nd.  These were of various lengths with the longest being near the equator in the eastern hemisphere.  This was still seen on the 4th when this was the main filament seen.  A multi-segment semi-circular filament was seen on the southern hemisphere on the 17th, 18th and 19th.  The number of filaments increased again towards the end of the month as seen on the 27th and 28th.

September 2012

The highest number of group seen during the month, eight, was on the 3rd.  The most prominence of these groups was AR 1560 and AR 1564.  AR 1560 was of type Eac at 4°N/129° which comprised of a collection of small penumbral and other sunspots where the total area was 190 millionths.  On subsequent days the number and size of sunspots within this group reduced such that by the 6th when the group was nearing the western limb it was just a Bxo group. AR 1564 was slightly larger than AR 1560 on the 3rd at 250 millionths and of type Eac at 13°S/69° – it too was a collection of penumbral and other sunspots. As this group progressed towards the central meridian the number of penumbral sunspots reduced while the number of pores increased. On the 7th, with the group just past the central meridian, just two penumbral sunspots were seen – however by the following day there were more penumbral sunspots. AR 1564 was last seen on the western limb on the 11th as a Bxo group.

By the 13th there were three groups on the disk – the largest being AR 1569 at 11°S/297° and of type Eac with an area of 220 millionths through the presence of three penumbral sunspots. As this group progressed towards the central meridian, it lost its following sunspots such that by the 18th it was of type Hax. AR 1571 was seen at almost the same latitude as AR 1569 but following by almost 20° - for example on the 18th it was at 12°S/280° of type Hsx with an area of 60 millionths.  No sunspots were seen in the northern hemisphere on the 16th and 17th.

The next observation on the 22nd showed AR 1575 at 9°N/181°and of type Eao to be the largest of three groups at 270 millionths. When next seen on the 29th it was of type Hsx close to the western limb. Also on the 29th Hhx and Hkx sunspots were seen in the southern hemisphere at 9°S/108° and 11°S/85° with areas of 120 and 260 millionths respectively (ARs 1579 and 1582).

Hydrogen Alpha:

There were numerous prominences seen on 3rd including a pair of nearby flame type on the NW limb with a maximum height of about 100,000 km, an arch type on the W limb and a tower type on the SE limb. A slightly reduced number of prominences were seen on the 7th and 14th.  Only three prominences were seen on the 16th and 29th but one of those on the 29th was as a complex structure on the SE limb with a maximum height of 100,000 km.

Filaments were seen on all five observations – of particular note was a semi-circular filament seen in the SW quadrant on the 16th and a pair of nearby filaments on the NW quadrant on the 29th.

November 2012

The first observation of the month, on the 3rd, shows only three small groups. By the 11th the number of groups had increased to seven which were all with the south-east quadrant.  The group nearest the central meridian was AR 1610 at 22°S/263° which was of type Dac and it had an estimated area of 190 millionths. Another moderately sized group was AR 1611 at 12°N/240° – it was also of type Dac with an area of 240 millionths.  AR 1614 was seen close to the eastern limb at 14°N/193° and of type Dsc.  On the 13th and 14th, AR 1610 had increased in size slightly to 230 millionths and had become type Eac. Meanwhile AR 1611 reduced in size to become an Hsx sunspot when seen on the 18th. AR 1614 because a complex Dac group by the 14th with an area of 220 millionths – it had become type Csi by the 18th.

Between the 14th and 18th, the largest group seen during the month, had appeared on the disk.  This was AR 1618 which was of type Cai at 9°N/134° with an area of 90 millionth – it was seen as an asymmetric leading penumbral sunspot followed by several pores. When seen on the 22nd the group was far more complex with irregular penumbral sunspots in the middle and following parts of the group – it was of type Ekc with an area of 430 millionths. It was also near the central meridian and seen with the protected naked eye. By the 25th it had decayed to a size of 250 millionths and of type Eac although the largest sunspot was at the following part of the group.

The final observation of the month, on the 30th, showed four groups which included two D type groups at a similar longitude and separated by a few degrees in latitude – AR 1625 at 14°N/341° and AR 1623 at 9°N/340°.  These two groups gave the appearance of a square of four penumbral sunspots.

Hydrogen Alpha:

Although prominences were seen on each of the four observing days on the 3rd, 11th, 18th and 25th, the most striking prominences were seen on the 18th – a tree shaped prominence was seen on the SE limb with the main “branches” being vertically and two horizontal either side of the prominence.  Close by and slightly towards to the equator a combined prominence/filament we also seen, although the prominence part was not as tall as the tree prominence. Many other filaments were seen for each of the four observations, especially again on the 18th when filaments were seen in both hemispheres and over all longitudes.

The observation on the 3rd showed plage near to AR 1604.  On the 11th plage was seen around AR 1610 and around AR 1614 which was near the eastern limb. On the 18th plage was seen around ARs 1612, 1614, 1619 and 1618 while on the 25th plage was still visible around AR1618, although the group had decayed since the 18th, but also around AR 1620 and 1622.

December 2012

Based on seven observations throughout the month, activity was quite low with all the groups seen being quite small.  On the 2nd the two nearby groups of AR 1625 and 1623 were seen of a similar appearance as at the end of November although the following sunspot of AR 1623 had almost disappeared to remove the square appearance of these two groups. These groups had disappeared by the time of the next observation on the 10th when just two groups were seen nearing the central meridian – AR 1630 of type Bxo at 18°N/253° and AR 1629 of type Dso at 12°N/239° and size 90 millionths. By the 12th AR 1630 had become type Dso with an area of 70 millionths. When last seen on the 17th AR 1629 a single Hsx sunspot close to the western limb.

The largest of five groups seen on the 17th was AR 1633 at 5°S/111° of type Eao and area 200 millionths. It was next seen on the 26th as an Hsx sunspot near the western limb. Also on the 26th AR 1635 was seen at 14°N/62° of type Dsc and area 200 millionths – this was the largest of the four groups seen on the 26th.

Hydrogen Alpha:

Observations on the 2nd and 16th showed several small prominences with the largest being on the SE limb on the 2nd as two nearby curved pieces of hydrogen. Similarly many small filaments were seen on both dates. Plage was seen around each the three groups seen on the 2nd (ARs 1621, 1625 & 1623).

Page created on 30 December 2011.