Disk Animations

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 2014

The recent moderately high activity continued again throughout the month with the majority of activity continuing to be in the southern hemisphere.

On the 2nd a complex and moderately large sunspot group, AR 1944, was seen near the eastern limb at 9°S/96° and of type Ekc. More of this group could be seen on the following day when it was of type Fkc: the irregular leader was the largest sunspot within the group and there were many smaller follower penumbral sunspots.  This group was quite impressive when next seen on the 6th being some 19° in length with an estimated total area of 1580 millionths – although the leader was the largest sunspot, there was now a very elongated irregular follower sunspot in the north-south direction. In between there were many smaller penumbral sunspots.  On the 7th the leader was on the central meridian and which now had several umbrae within it while the follower had decayed into many penumbral sunspots. The total area had reduced slightly to 1310 millionths. By the 9th both the leader and following sunspots had changed slightly and the total area had reduced again to 1010 millionths. There were further slight changes over the next few days as the group progressed towards the western limb. It was last seen on the 12th with an area of 1000 millionths (no observation was made on the 13th and it was not seen during the next observation on the 14th). AR 1944 was seen with the protected naked eye on the 3rd as one sunspot, on the 6th, 7th and 9th as two sunspots and on the 10th as one sunspot. For the observations when two naked eye sunspots were seen, it was the leader sunspot which appeared darker and more prominent compared to the follower. The return of AR 1944 was seen with the protected naked eye on the 31st.

Between the 3rd and 6th a new group had developed on the disk at a similar longitude as AR 1944 but in the northern hemisphere.  This group AR 1946 at 9°N/101° was of type Dac with an area of 90 millionths. By the following day, the 7th, it had grown to 230 millionths and by the 9th to 320 millionths through the development of an irregular follower. When last seen nearing the western limb on the 12th it was just a small Dao group.

Observations between the 14th and 25th showed several small groups.  The largest were AR 1959 at 24°S/240° on the 25th with an area of 300 millionths (type Dac) and AR 1960 at 16°S/236° also on the 25th with an area of 200 millionths (type Hax). 

Two high latitude southern groups were seen during the month: AR 1952 at 32°S/327° between the 11th and 19th (type Cai on the 14th) together with AR 1962 at 36°S/281° on the 19th (type Bxo).

Hydrogen Alpha:
On the 2nd a thin spike prominence was seen on the NW limb while on the disk a few filaments were seen together with plage around AR 1936/1940 and following the large AR 1944 group were also seen. On the 11th a triple spike prominence was seen on the NW limb while several filaments, one of which was particularly dark, were seen on the disk. Several plage were seen within and around AR 1944. On the 19th all the prominence and filaments seen were small – plage was seen around AR 1957 and the high latitude southern hemisphere AR 1962.

VLF:
The return of AR 1944 and AR 1946 around the eastern limb was detected by the presence of VLF flares on the 28th as shown below. According to the NOAA Space Weather Prediction Center (http://www.swpc.noaa.gov/ftpmenu/indices/events.html) the first three flare were from the returned AR 1944 (now AR 1967) while the forth was from the returned AR 1946 (now AR 1968).

                                                            VLF 23.4 kHz flare detections. 2014 January 28 (UT).

February 2014

The recent moderately high activity continued again throughout the month, especially towards the end of the month and with the majority of activity continuing to be in the southern hemisphere.

The return of the large group from January, now AR 1967, dominated the solar disk at the start of the month. On the 1st it appeared as a complex Fkc group at 11°S/112° comprising of small penumbral sunspots at the leading part of the group, a large asymmetric follower with an irregular penumbral sunspot in between (there were also a few other small sunspots within the group). It had an estimated area of 1200 millionths. On the following day, with the group nearing the central meridian, the three portions from the previous day had merged to form a large very irregular elongated sunspot. Within this there were many umbrae, the largest of which were towards the middle and following parts. Several small penumbral sunspots and pores were surrounding the main sunspot and the total area was 1620 millionths – an impressive sight. By the 8th only an irregular Hkx sunspot was seen nearing the western limb. AR 1967 was seen with the protected naked eye on the 1st, 2nd, 3rd and 6th.

To the north of the large sunspot group was AR 1968 at 11°N/112° of type Eac on the 1st with an area of 220 millionths (possibly the return of AR 1946) - it consisted of a string of small penumbral sunspots.  On the 2nd it had developed a larger follower but lost some of the leading penumbral sunspots to just pores. On the 8th, close to the limb, it had returned to a collection of several penumbral sunspots.

The observation on the 15th showed a collection of four groups at similar southern latitudes spread across the disk. The largest of these was AR 1974 at 11°S/352°. It was initially seen as a small Eac group on the 8th but by the 15th it had developed into an Ekc group with an area of 830 millionths through being comprised of many irregular penumbral sunspots. It was of a similar appearance and size on the 16th when seen approaching the western limb.  Three naked eye sunspots were seen on the 15th, the darkest being AR 1974, while two were (just) seen on the 16th.

On the 21st three nearby groups were seen approaching the central meridian.  These were AR 1984 at 16°S/221° type Bxo, AR 1981 type Eao at 6°S/215° and AR 1982 type Dac at 11°S/206°. The largest of these was AR 1982 at 340 millionths. On the following day it became more difficult to separate AR 1981 and 1982 as there was only about 5° difference in latitude and the following part of AR 1981 overlapping in longitude of AR 1982.  There was a greater longitude overlap between these two groups on the 24th. These groups were seen approaching the western limb on the 27th. 

The 24th showed the third return of AR1944/AR 1967 as a thin penumbral Hkx sunspot very close to the limb at 13°S/106° (now AR 1990). By the 26th it could be seen that the group had decayed significantly since its previous rotation since it was now a small single Hax sunspot with an area of 160 millionths. On the 27th it had grown slightly to 220 millionths when a couple of leading pores were also seen. The solar disk was seen with 11 groups on the 27th, the highest seen during the month.

Hydrogen Alpha:
The most interesting Hα activity from four observations was on the 2nd when three flares were seen between 13h 55m to 14h 45m UT (with a cloud break between 14h 05m to 14h 25m). These flares were seen within the large sunspot group AR 1967 and the northern group AR 1968 – various areas of plage were seen within these groups at the beginning of the observing period. From 14h 02m until the clouds at 14h 05m, a compact bright region was seen within AR 1967 (a M1.7 flare) – this flare was not seen after resuming observations at 14h 25m. At this time a flare, C7.8, was seen with AR 1968 as elongated bright areas. After this flare faded, another C7 flare brightened within the same group between 14h 33m to 14h 45m – this had the appearance of a ribbon within the group.

2014 February 02, 1317 UT. Large sunspot group AR 1967.

March 2014

The moderately high activity of recent months continued but in the form of many small/medium sized groups rather than fewer larger groups.  Based on 17 observations spread throughout the month, a total of 39 separate groups were recorded from the 1st to 30th.  Again the southern hemisphere was the more dominant with several groups seen at high southern latitudes. 

On the 1st the largest group seen was AR 1991 at 24°S/89° of type Eao which just comprised two irregular penumbral sunspots with a total area of 280 millionths. By the 5th there had been an increase in the number of sunspots spread throughout this group but the penumbral sunspots had reduced in size to give an area of 120 millionths. The group continued to decay with just an Hsx sunspot seen on the 7th and an Axx sunspot on the 9th when it was nearing the western limb.  The next moderately sized group was AR 2002 which was initially seen as a Bxo type near the western limb on the 9th at 17°S/322°. By the following day the group had developed into type Dac with an area of 240 millionths – the follower was the largest penumbral sunspot.  When next seen on the 14th AR 2002 had formed into an Eac group, now near the central meridian, with an area of 290 millionths with many small penumbral sunspots spread throughout the group. It was of similar form on subsequent days and was last seen on the 17th.

On the 14th a solitary Hax sunspot, AR 2005, was seen at 12°N/263° with an area of 280 millionths. It was of a similar type on the 15th but on the 16th two small sunspots had formed nearby. Just one of these additional sunspots was seen on the 17th and by the 20th the group was a single Hax sunspot once again. It was last seen on the 24th very close to the western limb. During the latter part of the month, the largest group was AR 2014 which was seen near the eastern limb on the 20th as a Dso group at 13°S/168°. By the 24th it changed slightly to type Dac with an area of 240 millionths and it comprised of several small penumbral sunspots throughout the group with the leader being the largest. As the group progressed towards the western limb, it reduced in size such that on the 29th it was 150 millionths and type Dso. It was last seen as type Dso very close to the limb on the 30th when it comprised of just two small penumbral sunspots.

Hydrogen Alpha:
Based on 9 observations, the most striking prominences were a combined filament/prominence on the 9th on the SE limb, another filament/prominence on the 28th on the SE limb and a twin flame prominence on the NE limb also on the 28th. Many long thin filaments were seen throughout the month while an extensive region of plage were seen around AR 1998 (a Csi group at 10S/359) on the 9th.

                                                        VLF 23.4 kHz flare detections. 2014 March 12 (UT).

April 2014

As during March the moderately high activity continued through the presence of many small/medium sized groups.  Although the southern hemisphere was the more dominant there were many groups in the north. 

The largest of five group seen on the 5th was AR 2021 at 13°S/70° of type Dac at 280 millionths which consisted of several small penumbral sunspots throughout the group. On the 8th a Dso group was seen near the eastern limb – AR 2032 at 12°N/270°. As this group rotated on to the disk, it was type Esc with, on the 10th, an area of 320 millionths. It lost its middle penumbral sunspot by the 12th to leave a few pores between the leader and follower sunspots. Even these had disappeared by the 14th with the group just past the central meridian.  AR 2032 was last seen close to the western limb on the 19th.

Also on the 14th a small Dsc group had developed on the disk at 16°S/246° at 60 millionths – AR 2036 was comprised of many small penumbral sunspots. By the following day its appearance had changed quite significantly to become two main irregular penumbral sunspots with an area of 350 millionths and was visible with the protected naked eye. On the 16th the follower had increased in size while the leader had split into two – the group was now of type Dkc with an area of 380 millionths and again visible with the protected naked eye. On this date it was near the central meridian. Observations on the next 3 days, the appearance of this group changed each day but it was of type Dac on each date. AR 2036 was last seen close to the western limb on the 21st.

The period 15th to 19th showed an increase in the number of groups visible in both hemispheres (although there were more in the south). For example on the 19th, ten groups were seen – in addition to AR 2036, the largest groups were AR 2034 at 6°N/243° of type Eao at 370 millionths, AR 2035 of type Dac at14°S/220° at 280 millionths and AR 2042 at 17°N/163° of type Dao at 260 millionths. By the 26th AR 2042 was now of type Hsx and it was last seen near the limb on the 27th. Also on the 27th a single Hsx sunspot had rotated onto the disk – by the following day a follower had appeared to make this group, AR 2049 type Dso at 7°S/15°. On the 30th it had an area of 310 millionths and was of type Dac.

Hydrogen Alpha:
A faint cloud type prominence was on the NW limb on the 14th – a thin piece of hydrogen was seen extending down from one end of the cloud to the limb. On the 15th a flare close to the SE limb was in progress at the start of the observing period at 12h 50m UT. Just further onto the disk was an almost semi-circular filament. The C3.6 flare, seen as an almost circular region, had faded by 13h 00m UT. On the 19th at 15h 30m UT a bright short spike prominence was seen on the SW limb until 15h 40m. This region was quite active with a nearby prominence seen to extend in height over the next 10 minutes. A complex S shaped prominence was seen on the NW limb on the 21st – it comprised several segments that were detached from the limb up to a height of 90,000 km.

May 2014

Activity continued at moderately high levels throughout the month but again this was only due to the presence of many small/medium sized groups.  The southern hemisphere was the more dominant again especially during the latter part of the month when no northern groups were seen from all observations made between the 22nd & 25th and 29th & 31st inclusive. 

The first observation of the month on the 3rd showed three similarly sized southern D type groups. These were AR 2051 at 10°S/57° of type Dko at 270 millionths, AR 2047 at 18°S/48° of type Dac at 270 millionths and AR 2049 at 7°S/14° of type Dac at 280 millionths. The irregular leading sunspot of AR 2051 had decayed into several smaller penumbral sunspots by the following day and it had decayed further when last seen near the limb on the 5th. AR 2047 similarly reduced in size as it neared to limb, last being seen as an Hsx sunspot on the 6th. AR 2049 continued as a D type until it lost it follower penumbral sunspots by the 6th when it was of type Csi at 150 millionths and then to an Hsx group on the 7th at 90 millionths.

Also on the 6th two northern E type groups had rotated onto the disk. The first of these was AR 2055 at 13°N/270°. On the 7th it had an area of 430 millionths but when next seen on the 13th, it had reduced in size to 270 millionths and now of type Eac. The leader was to largest sunspot in the group. Over the next few days it became type Dao, Cso and then Hsx on the 16th when close to the western limb. The other group, AR 2056 at 4°N/259° was of type Dai on the 14th at 190 millionths. Although it lost many of its smaller sunspots as it progressed towards the limb, it was of type Eao when last seen on the 17th.

From the 17th onwards the number of groups reduced to four or five from the 22nd onwards.  Of particular note during this period was AR 2065.  This group was initially seen as an Axx sunspot on the 16th at 17°S/144° not too far from the eastern limb.  Nothing of this group was seen again until the 23rd when a Dso group was seen at 19°S/147°. This group had an estimated area of 190 millionths on the 24th before nearing the limb on the 25th. The month ended with five small southern groups, the largest being AR 2075 of type Cso at 8°S/17° with an area of 60 millionths.

Hydrogen Alpha:
On the 4th, at 16h20m UT, a ‘pick-axe’ shaped prominence was seen on the NW limb together with a faint cloud of hydrogen suspended above the SW limb. An extensive and elongated region of plage was seen around AR 2060 on the 18th together with other regions of plage around ARs 2063, 2066 and 2068. On the 31st a series of prominence were seen along the SE limb.

June 2014

On the 4th a small Bxo group was seen near the eastern limb at 11°S/260°. This group, AR 2080, developed into a small Dao group by the following day, into a Dai group by the 6th and then into type Dac on the 7th with an area of 200 millionths. This development continued such that on the 8th AR 2080 comprised of an irregular leading penumbral sunspot and several small following penumbral sunspots. The leading sunspot developed further when seen on the 10th when the group was seen at its maximum area of 340 millionths. As it neared the limb, fewer sunspots were seen such that on the 13th only an extended Dko sunspot remained. On the 6th a Bxo group developed on the disk just to the south and east of AR 2080 – this was AR 2085 at 18°S/253°. This group also developed rapid such that by the following day, it was of type Dac and by the 10th it was of type Ekc at 470 millionths with a larger leader than AR 2080. By the 12th it has also started to decay such that it was last seen as type Eko on the 13th.

On the 10th an Hsx sunspot was seen close to the limb – this was AR 2087 at 18°S/154°. By the 12th it could be seen that this group was of type Dsc. It was of the same type on the 13th with an area of 230 millionths. During this period it was very active in Hα (see below) but this was not obvious in white light. On the 17th AR 2087 was just past the central meridian was of type Dsc with an area of 180 millionths. It was last seen as a Cso group on the 21st close to the western limb.

Activity was particularly low on the 23rd when only one group was seen – AR 2096 at 10°N/353°. Additional small group was seen on subsequent observations but on the 29th two new larger groups appeared around the eastern limb – AR 2104 and 2107 at 8°S/269° and 20°S/260° respectively. AR 2104 was seen as an irregular Dac group on the 30th while AR 2107 just comprised on two asymmetric penumbral sunspots to form a Dao group.  

Hydrogen Alpha:
On the 1st several prominences were seen on the E limb including a spike prominence with a cloud of hydrogen extending from the end of the spike to an estimated height of 120,000 km. An observation on the 8th showed a long broken S shaped filament towards the middle of the disk. This was also seen on the 10th but only as two fragments. Also on the 10th at 16h 45m UT a small bright region was seen on the disk near the E limb – this was a C1.5 flare in AR 2087 (the same region that produced X2.2 and X1.5 flares earlier the same day). Nothing was seen at 17h 45m. A further flare was seen within the same AR on the 12th at 18h 25m – two small bright regions were seen (there had been a M1.3 flare at 18h 13m and a C7.3 at 18h 23m). The flare had subsided by the end of the observing session at 18h 45m UT. A nice arch prominence was seen on the 21st on the NE limb at 18h 20m while on the opposite limb a floating prominence, parallel to and about 100,000 km above the limb was also seen.

July 2014

An unusual month: moderately high activity during the first week including four naked eye sized sunspots before significantly reducing towards the middle of the month including no sunspots on the 17th and then slowly increasing activity towards the end of the month.

On the 1st all four northern groups were all small and of type Bxo.  However, in the south there were two larger complex groups which were at almost the same longitude.  AR 2104 of type Dkc at 10°S/268° was slightly to the north and west of AR 2107 of type Dao at 20°S/260°. Both groups had passed around the limb a few days previously.  AR 2104 comprised of a symmetric leader and a larger irregular follower which was elongated in latitude: it had a total estimated area of 470 millionths. By the following day, the follower has split such that there were now several irregular sunspots within the group with an area of 590 millionths. On the 3rd several of the sunspots had merged to give a much larger irregular leader.  Next the leader started to split into several sunspots and the followers reduced in size such that by the 8th AR 2104 was a small Dsi group at 120 millions.  The other southern group from the 1st, AR 2107, was of type Dac up to the 6th when it lost it leading smaller sunspots to comprise of a single asymmetric sunspot with a few surrounding pores. It obtained an area of 380 millionths on the 2nd while becoming smaller on each subsequent day to being 140 millionths on the 8th when it was a single Hax sunspot.

On the 2nd two small southern groups has appeared near the eastern limb.  The first of these, AR 2108, had formed on the disk at 7°S/239° as a small Cso group. By the 4th a follower penumbral sunspot had developed to form a Dsi group of area 110 millionths. Significant development took place such that just two days later, on the 6th, AR 2108 has become a complex Dkc group of 580 millionths (i.e. its area increased by a factor of five in two days). It comprised of an irregular leader containing many umbrae, a more symmetric follower and many small pores around the group. On the following day, the leader had changed shape to become a larger more symmetric sunspot: now the total area was 740 millionths. This group had changed again on the 8th: now the leader was slightly smaller but the following sunspots had merged into one sunspot and the area increased slightly to 770 millionths.  The other group, AR 2109 at 7°S/219°, was initially an Hsx sunspot close to the eastern limb. By the 3rd a smaller follower appeared from around the limb. Additional sunspots developed within the group by the 4th but by the 6th a complex group with a dominant leader had formed: it had an area of 610 millionths. Over the next two days, the leader reduced slightly but it still had a area of 600 millionths and was of type Dkc on the 8th.

AR 2104 was seen with the protected naked eye on the 2nd, 3rd and 4th while on the 6th four naked eye sunspots were seen: AR 2104, 2107, 2108 and 2109 with the latter two groups being much easier to detect. On the 7th three sunspots were seen with the protected naked eye while on the 8th, two were seen (AR 2108 and 2109).

The next observation on the 15th showed a very different level of activity – just one small Hsx sunspot, this being an Hsx sunspot at 9°N/163° with an area of 30 millionths. On the 17th no sunspots were seen while on 18th three small groups has developed on the disk. Two of these had decayed by the 21st when only a Cso group at 20°S/65° with area 50 millionths remained. Although the number of groups increased towards to end of the month, none were particularly large. On the 31st eight groups were seen, the largest being AR 2130 at 7°S/229°, of type Dac at 330 millionths.

Hydrogen Alpha:
On the 19th a cloud of hydrogen well above the NE limb was seen while on the 22nd a tall spiky prominence with a curved piece of hydrogen almost parallel to the limb sitting on top of the spike was seen on the NW limb. This latter prominence had an estimated height of 110,000 km above the limb. On the 24th a flame type prominence was seen on the SW limb. Numerous filaments and regions of plague were seen throughout the month.

August 2014

Activity was moderately high during the month but all groups seen were not particularly large. For example the largest of eight seen on the 1st was AR 2132 at 18°S/210° of type Dac at 310 millionths. It had been of type Axx the previous day when it was close to the eastern limb. It remained a D type group over subsequent days before extending in longitude to become a small type Eac group on the 6th. As it neared the western limb AR 2132 reduce to type Hsx on the 10th.  To the north and west of AR 2132 on the 1st was AR 2130 at 06°S/228° of type Dac and size 190 millionths. Although it reduced in size on subsequent days, it extended in longitude to become type Fao on the 2nd through the presence of follower pores. A similar number of small sunspots were seen on the 3rd and 5th but by the 7th, the group was last seen as type Bxo.

Towards the middle of the month, the number of groups reduced to just three on the 10th. One of these was AR 2135 at 13°N/128° which was initially seen as type Cso on the 6th close to the eastern limb.  A follower sunspot developed by the following day and it was of type Eai on the 9th with an area of 230 millionths. As it progressed towards to central meridian, it started to reduce in size and type, to be a single Hsx sunspot on the 16th when near the western limb.

Although the number of group seen increased again, with nine seen on the 23rd, none of these were particularly large. The most interesting was AR 2146 at 10°N/346° which was initially seen at an Hsx sunspot close to the eastern limb on the 17th. This was accompanied by small pores on the 20th and 21st and then by another penumbral sunspot on the 23rd which appeared to merge together by the following day to make a complex penumbral sunspot – this together with another small penumbral sunspot made the group type Dko with an estimated area of 310 millionths. It was last seen as an Hax sunspot close to the western limb on the 27th.

Hydrogen Alpha:
An extensive hydrogen ‘cloud’ prominence was seen above the SE limb on the 2nd which appeared attached to limb on the following day, having rotated further onto the solar disk. Another detached prominence was seen on the SW limb on the 23rd as a series of elongated blobs of hydrogen. A more complex prominence was seen on the same day on the opposite NE limb – this included a jet extending parallel to the limb towards the solar equator.

Filaments were seen on each of five observing days – long examples were seen on the 2nd, 3rd and again on the 23rd.  Plage was seen associated with AR 2130 and 2132 on the 2nd and 3rd, AR 2135 on the 9th, AR 2139, AR 2141 and 2143 on the 17th and with AR 2146 and AR 2149 on the 23rd.

September 2014

Activity was moderately high during the month but all groups seen were not particularly large. For example the largest of eight seen on the 1st was AR 2132 at 18°S/210° of type Dac at 310 millionths. It had been of type Axx the previous day when it was close to the eastern limb. It remained a D type group over subsequent days before extending in longitude to become a small type Eac group on the 6th. As it neared the western limb AR 2132 reduce to type Hsx on the 10th.  To the north and west of AR 2132 on the 1st was AR 2130 at 06°S/228° of type Dac and size 190 millionths. Although it reduced in size on subsequent days, it extended in longitude to become type Fao on the 2nd through the presence of follower pores. A similar number of small sunspots were seen on the 3rd and 5th but by the 7th, the group was last seen as type Bxo.

Towards the middle of the month, the number of groups reduced to just three on the 10th. One of these was AR 2135 at 13°N/128° which was initially seen as type Cso on the 6th close to the eastern limb.  A follower sunspot developed by the following day and it was of type Eai on the 9th with an area of 230 millionths. As it progressed towards to central meridian, it started to reduce in size and type, to be a single Hsx sunspot on the 16th when near the western limb.

Although the number of group seen increased again, with nine seen on the 23rd, none of these were particularly large. The most interesting was AR 2146 at 10°N/346° which was initially seen at an Hsx sunspot close to the eastern limb on the 17th. This was accompanied by small pores on the 20th and 21st and then by another penumbral sunspot on the 23rd which appeared to merge together by the following day to make a complex penumbral sunspot – this together with another small penumbral sunspot made the group type Dko with an estimated area of 310 millionths. It was last seen as an Hax sunspot close to the western limb on the 27th.

Hydrogen Alpha:
An extensive hydrogen ‘cloud’ prominence was seen above the SE limb on the 2nd which appeared attached to limb on the following day, having rotated further onto the solar disk. Another detached prominence was seen on the SW limb on the 23rd as a series of elongated blobs of hydrogen. A more complex prominence was seen on the same day on the opposite NE limb – this included a jet extending parallel to the limb towards the solar equator.

Filaments were seen on each of five observing days – long examples were seen on the 2nd, 3rd and again on the 23rd.  Plage was seen associated with AR 2130 and 2132 on the 2nd and 3rd, AR 2135 on the 9th, AR 2139, AR 2141 and 2143 on the 17th and with AR 2146 and AR 2149 on the 23rd.

October 2014
Activity during the month was dominated by the appearance of the large sunspot group AR 2192. This group was first seen on the 18th close to the eastern limb at 12°S/247° as an Fkc type where the follower was the largest penumbral sunspot. From this observation it was clear that this was a large sunspot group – indeed it became the largest of this solar cycle. On the following day more of the large irregular follower could be seen which included a main umbra and several smaller umbra sunspots. Its total area was estimated at 2200 millionths. By the 21st AR 2192 became much more complex with many umbrae and several regions of photosphere within the main penumbral sunspot and its area grew to 2770 millionths. On the following two days the group remained a similar size although more photosphere could be seen in the middle portion of the group. In fact by the 27th there had been a split with the follower being the largest penumbral sunspot – its area had reduced to 2280 millionths. AR 2192 was last seen on the 28th.  Throughout its passage across the solar disk, AR 2192 remained type Fkc.

AR 2192 was seen with the protected naked eye on the 19th, 20th, 21st, 22nd, 23rd, 25th, 27th and 28th (from the 21st to 23rd it was seen as an elongated sunspot while on the 25th two distinct naked eye sunspots were seen but on the 27th and 28th it was once again seen as one sunspot).

Hydrogen Alpha:

The most spectacular Hα event during the month was the observation of a X2.0 solar flare within AR 2192 on the 27th. This observation began at 14:20 UT when multiple bright regions were seen within the group. The size and brightness of these changed rapidly over the next 10 minutes as the flare developed past type X1 at 14:25 towards the broad X2 peak at 14:47 UT. A switch from visual observation to imaging showed flares within the main penumbral sunspot (close to the two main umbrae), in a region between the leader and follower together with a thin strand of bright hydrogen towards a circular flare region to the south west away from the group itself. These bright regions gradually faded towards the end of the observing period at 15:30 UT when the flare was still of type M4 (see images below).

In addition a C5.8 flare was seen within AR 2192 on the 19th: at 12:20 UT a bright ribbon was seen to the north of the main penumbral sunspot while by 12:25 UT just two bright patches remained. Other Hα activity included an extensive hedgerow prominence along the E limb on the 5th which extended for some 20° along the limb. Several small filaments were seen around AR 2192 on the 23rd.  Long filaments were seen on the 23rd, 27th and 31st, the latter being a combined prominence/filament extending over the NW limb. A high arch/loop prominence was seen on the E limb on the 31st with the maximum height being about 100,000km.

VLF Receiver:

Many solar flares were detected during the month using a 23.4 kHz VLF receiver include three X flares associated with AR 2192 that occurred during daylight hours as shown below:


November 2014

On the 4th a small Dsc group, AR 2205, was seen close to the eastern limb at 16°N/12°. By the 7th it had become an Eac type with an area of 250 millionths: it comprised a number of small penumbral sunspots and it was the largest group on the solar disk. The shape, size and number of penumbral sunspots had changed by the 9th (now a Dac group) and again on each of the next two following days indicating an active group (AR 2205 was close to the central meridian on the 10th). Its total area remained similar on each of these days before reducing to 100 millionths when AR 2205 was last seen on the 12th.

Also on the 12th an extensive area of faculae was seen near the limb in the south-east quadrant which indicated the expected return of the large October group AR 2192. Indeed, the next observation on the 19th showed a large irregular penumbral sunspot at 13°S/243°, AR 2209. Within the sunspot were several umbrae together with a region of photosphere near the centre of the sunspot. In the leader position within the group was a smaller regular penumbral sunspot. On the following day a few pores were seen between the leader and follower sunspots: the group was of type Fko with an estimated area of 1050 millionths. The next observation on the 24th showed AR 2209 close to the western limb and of a similar form as previously (the region of photosphere still visible within the larger follower sunspot). AR 2209 was seen with the protected naked eye on the 19th and 20th.

Another naked eye sunspot was first seen on the 20th close to the limb at 12°S/163°. On the 24th AR 2216 was seen as type Dkc with an area of 620 millionths. The majority of the size of the group was through the irregular leader penumbral sunspot. This group had drastically reduced in size by the 29th when it was of size 120 millionths and type Dao. On the 30th it comprised of just a small leader & follower sunspot. AR 2216 was seen with protected naked eye on the 24th.

Observations on the 29th and 30th showed an increase in the number of groups seen with nine on each date (the highest of the month). Included was AR 2222 at 18°S/83°. On the 29th this bipolar group of type Eac comprised an asymmetric leader, an irregular follower and several pores in between.  It had an area of 520 millionths. On the 30th the leader extended slightly while the follower reduced in size slightly to make the group type Eko with area 460 millionths. AR 2222 was seen with protected naked eye on the 29th and 30th.

Hydrogen Alpha:

On the 1st an extensive hedgerow prominence was seen on the SW limb, while on the NE limb a small combined filament/prominence was seen together with small detached prominence closer towards the equator. On the 9th an irregularly shaped prominence was seen on the SE limb: several streams of hydrogen were seen extending almost parallel to the solar limb. A small loop prominence was also seen on the NE limb.  A spike and arch prominences were seen on the western limb on the 29th. A couple of long filaments were seen in the SW quadrant on the 29th. The most extensive plage seen from the three observations was on the 29th around AR 2222.

VLF Receiver:

Several solar flares were detected during the month using a 23.4 kHz VLF receiver include an M2.3 flare during the sunset part of the VLF plot as shown below:

On the 4th a small Dsc group, AR 2205, was seen close to the eastern limb at 16°N/12°. By the 7th it had become an Eac type with an area of 250 millionths: it comprised a number of small penumbral sunspots and it was the largest group on the solar disk. The shape, size and number of penumbral sunspots had changed by the 9th (now a Dac group) and again on each of the next two following days indicating an active group (AR 2205 was close to the central meridian on the 10th). Its total area remained similar on each of these days before reducing to 100 millionths when AR 2205 was last seen on the 12th.






The naked eye group from the end of November, AR 2222 at 18°S/83°, had changed from a Eko type on November 30 into a single Hkx sunspot on the 6th. It was a quite irregular shaped sunspot and it had an area of 560 millionths. It was of a similar shape on the 7th and was seen very close to the western limb on the 8th. Four groups were seen on the 8th – on subsequent days more groups were seen such that by the 11th there were seven and by the 14th eleven. One of these was seen at an unusually high latitude for this part of the solar cycle. This group, AR 2236, was first seen on the eastern limb on the 11th at 30°N/240°. Observations up to the 20th showed AR 2236 as a single Hax type with a maximum area of 170 millionths on the 14th.

Between observations on the 13th and 14th, a Dso group had developed on the disk at 16°S/238°. This group, AR 2242 grew rapidly between the 14th and 16th with its area increasing from 80 to 680 millionths when it was of type Dkc and comprised of an irregular leader, a smaller irregular follower and with many pores throughout the group. With this group near the central meridian on the 17th, the leader had grown again, extending in longitude and containing many umbrae. The size of the following penumbral sunspots had reduced. Its area was estimated at 790 millionths. The leader had increased again by the 19th when AR 2242 became type Ekc with an area of 1140 millionths. By now the main penumbral sunspot was quite complex in shape with many umbrae within it. A small penumbral sunspot had formed in the leading position within the group while just a small follower was seen. By the next day the main sunspot had split into three parts and its area almost halving to 650 millionths. AR 2242 had rotated around the western limb by the next observation on the 24th.

During this period another medium size group developed slightly to the north and east of AR 2242.  This was AR 2241 at 8°S/216° and it was initially seen as an Hsx on the 13th near the limb. It was a small Dsc group on the 14th before becoming type Eac on the 16th with an area of 180 millionths. By the following day it developed quite rapidly by doubling its size to 440 millionths and comprising a string of penumbral sunspots with the follower being quite irregular. This group grew slightly by the 19th at 570 millionths (and near the central meridian) before reducing to 430 millionths on the 20th. Further decay must have taken place since when seen next on the 24th only an Hsx sunspot remained.  AR 2241 was last seen near the western limb on the 25th.  AR 2242 and AR 2241 were seen with protected naked eye on the 19th (AR 2241 comprised of two naked eye sunspots).

2014 December 19. AR 2241 (left) and AR 2242 (right).  East left.

From the 24th to the end of the month six groups were seen on each of five observing days, none of the groups were of particularly note. The largest seen was AR 2253 at 4°S/357° of type Eac and size 390 millionths on the 31st.

Hydrogen Alpha:

On the 6th an irregular arch prominence was seen on the SE limb, there were a few filaments including one which had the appearance of a 90° bend and plage around AR 2222. On the following day the arch prominence had disappeared but the bent filament was still visible but included a slightly less sharp bend. Two small neighbouring spike prominences were seen on the NW limb. Observing on the 14th a multiple arch prominence was seen on the SE limb while near equator on the E limb a faint tree shaped prominence was seen – some of the ‘branches’ were disconnected from the main ‘trunk’. Plage was seen around AR 2242.

Page created on 31 December 2013.