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.
On the 1st AR 1036, at 27°S/54°, was still on the disk and of type Dao with an area of 100 millionths. With the group nearing the western limb, it started to decay such that on the 4th it was of type Cao. No sunspots were seen on the 5th. On the 8th an Axx spot was seen at 28°N/244° and near the eastern limb (AR 1040). By the time of the next observation on the 17th, this group was now near the western limb and of type Dao. An observation on the 26th showed a small Hsx group at 23°S/57° (AR 1041). This was not seen on the 31st but there was another group, AR 1043, at 25°N/323° and of type Cso with an area of 30 millionths.
From just four observations, all the prominences seen were small. Plage was seen around AR 1039 on the 1st, 2nd and 3rd with bright plage being seen on the 3rd. A region of plage was seen around AR 1040 on the 17th. Small filaments were on the 1st and 17th.
AR 1043 was seen at 23°N/324° on the 1st as it approached the central meridian when it was of type Hsx with an area of 30 millionths. By the next observation on the 6th it had reduced to a single Axx spot. However another northern group was seen on this date, AR 1045 at 23°N/253°, which was of type Dai with a total area of 90 millionths. By the 10th, this group had increased its longitudinal extent to become type Fac but its overall area remained almost unchanged. By the following day, most of the small sunspots between the leader and follower had decayed to leave two distinct collections of sunspots. The group decayed further such that on the 13th, with the group nearing the western limb, only a Bxo type group remained.
Also on the 10th a Csi group was seen at 24°N/186° (AR 1046). By the 11th several penumbral sunspots had developed at the following part of the group to give a Dao group with an area of 140 millionths. More spots were seen within this group on the 13th but again the penumbral spots were all in the following part of the group. On the 17th a pair of Axx spots were all that remained of AR 1046.
On the 17th there were two other groups on the disk, AR 1049 at 18°S/119° of type Cso and AR 1048 at 22°N/97° of type Axx. By the 20th only AR 1049 remained, now of type Dsi with an area of 70 millionths. By the time of the observation on the 27th only a Hsx group at 15°N/324°, AR 1051, was visible.
On the 6th, a arch type prominence was seen on the NE limb with two nearby filaments, a string a fainter prominences along the SE limb and plage around AR 1045. On the 20th a flame shaped prominence was seen on the NW limb, two prominences on the SE limb one of which was a very thin curved shape and plage around AR 1049.
The observation on the 1st showed two small Hsx sunspots – AR 1051 at 16°N/323° and AR 1052 at 16°S/351°. By the following day, these were joined by a Bxo group to the south of AR 1052 at 22°S/359° (AR 1053). AR 1051 had decayed to an Axx sunspot on the 4th while the other two groups were nearing the western limb. There was a blank disk on the 5th and 6th before an single Axx sunspot was seen at 23°N/238° on the 7th (no AR number).
The next observation on the 14th showed a moderately sized group near the central meridian. This group, AR 1054, was of type Dac at 15°N/150° with an area of 210 millionths. By the following day the group began to decay with the leading penumbral sunspot now being much smaller and there also being fewer spots within the group. Although the group was of similar appearance on the 16th, by the 19th only an Axx sunspot was seen near the western limb. Another Axx group was seen on the 19th at 18°N/64° – AR 1056. This was the only group seen on the 21st, now as a small Csi group.
Observations on the 27th and 28th showed the largest group of the month – AR 1057 at 15°N/322° which had an area of 400 millionths on the 28th when it was of type Dki. The largest penumbral sunspot was the follower. An Hsx group, AR 1059 at 22°S/265°, was also seen near the eastern limb on these two dates.
Hα activity from 5 observations was dominated by filaments although prominences were seen, they were all quite small. On the 6th and 7th a NE quadrant filaments near the limb was also seen extending above the limb to form a prominence. Several small filaments were seen in the northern hemisphere on the 14th along with plage around AR 1054. On the 21st 5 filaments were seen including one associated with AR 1056 where a small region of plage could also be seen. Smaller filaments were seen on the 28th – plage was also seen around AR 1057.
Five groups were seen during the month. On the 1st AR 1057 was seen with a reduced size of 230 millionths compared to the end of March and it now consisted of a single Hax sunspot at 17°N/317°. AR 1059 also from the end of March was visible at 22°S/265° as a small Hax spot. AR 1057 was last seen on the 4th close to the western limb. Meanwhile AR 1059 decayed on the disk and was last seen on the 5th as an Axx group. On the 4th AR 1060 was first seen close to the eastern limb at 23°N/177° as an Hsx spot. On the following day it was a Cso group with an area of 50 millionths before returning to an Hsx spot on the 6th and thereafter decaying.
AR 1061 formed on the disk just past the central meridian on the 5th as a Bxo group at 13°N/231°. By the following day it had formed into a small Dso group with an area of 90 millionths. By the 8th only the leading penumbral sunspot remained which was last seen near the western limb on the 9th. After a blank disk on the 11th an Axx sunspot, AR 1062 at 18°S/134°, was seen near the central meridian on the 12th and 13th only. The 15 observation from the 14th to 30th all showed blank disks.
Although prominences were seen on each of the 15 observations made during the month, none were particularly large. However many filaments were seen on each observation including 7 on the 8th. The majority of the filaments were in the northern hemisphere. Plage was seen around AR 1061 on the 5th and around AR 1062 on the 13th.
The four groups seen at the beginning of the month were all small. AR 1064 was seen on the 1st only as an Axx sunspot at 15°N/224°. On the 3rd three groups were seen – AR 1063 at 18°N/262° as a single Axx sunspot, AR 1066 at 25°S/207° as a Cso group with an area of 30 millionths and AR 1067 at 22°N/175° as a Bxo group. On the 4th AR 1063 had disappeared while AR 1067 had decayed to a Bxo group. Observations every day from the 10th to 20th showed a spotless disk.
On the 21st a Bxo group appeared on the disk at 14°S/317° (AR 1072). By the following day this group had developed into a Cso type with an area of 60 millionths. The group was of similar appearance on the 23rd when it was near the central meridian. By the 24th the leading penumbral sunspot had decayed slightly while by the 26th all the following sunspots had decayed. This single Hsx sunspot was seen near the western limb on the 28th. There was blank disk on the final observation of the month on the 30th.
The most striking prominence of the month was seen on 5 consecutive days between the 20th and 24th. This prominence, on the NW limb, was initially seen as two nearby spike prominences before appearing as an arch type on the 21st. The arch structure continued on the 22nd with the main part looking like the “Eiffel Tower”. The structure had reduced in height by the 23rd and started to separate into three parts. It was finally seen at a reduced height on the 24th.
Filaments were seen on each of the 13 Hα observations made during the month. A filament seen on the 17th on the NE limb also extended over the limb as a small prominence. A remarkable filament was seen on the 30th – this was initially seen at 1550 UT as two nearby curved filaments but by 1616 UT they had formed into a single filament in the shape of an almost perfect semi-circle loop. Observations over the next two hours showed the middle portion of the loop disappearing to leave two curved filaments.
Plage was seen around AR 1066 on the 3rd and around AR 1072 from the 21st to 24th. Plage was also seen on various occasions during the month that was not associated with observed sunspot groups, including on the 4th, an extended area of plage at a high northern latitude.
AR 1076 was seen on the 2nd at 20°S/196° consisting of a Dsc group just past the central meridian. By the following day the following sunspot had increased in size to become the largest in the group with the total area being 200 millionths. On the 4th this group had started to decay such that on the 5th it was of type Cao and it was last seen as a Hsx sunspot near the western limb on the 6th. On the 4th and 5th an Axx sunspot was seen at 19°N/181° (AR 1077).
On the 8th AR 1078, of type Dso, was seen at 20°S/142° having formed on the disk. On the 9th it consisted of 3 penumbral sunspots while it was last seen on the 11th as an Hsx sunspot on the western limb. Two other small groups were also seen in the SW quadrant and at a similar latitude: AR 1079 at 25°S/121° on the 9th and 12th and AR 1080 at 23°S/107° on the 11th and 12th.
AR 1081 also formed on the western disk but in the north at 22°N/100° as type Bxo on the 11th before developing into type Dsc with an area of 150 millionths on the 12th. As the group neared the limb it became type Hsx on the 14th. No sunspots were seen on the 17th.
Two Axx groups were visible on the 19th – AR 1082 at 31°N/298° and AR 1083 at 19°N/331°. Only AR 1082 was seen on the following day when it was a small Dso group with a total area of 60 millionths and near the central meridian. It has decayed type Cso on the 23rd before becoming type Axx on the 24th. On the 26th and 27th an Hsx sunspot was seen close to the eastern limb at 19°S/143° (AR 1084).
On the 9th and 11th a prominence was seen “floating” above NW limb – its appearance changed slightly between the two dates with a combined prominence and filament seen on the 11th further towards the north. On the 17th a tall arch prominence was seen on the SW limb – its height was estimated to be 100,000 km. On the 19th a string of prominences were seen on the NE limb spanning some 15° along the limb.
Many filaments were seen during the month. Of particular note was a moderately long filament on the NE quadrant on the 4th (20° long), several filaments around AR 1081 on the 11th and another long filament in the north on the 19th (also about 20° long).
Plage was seen around AR 1076 on the 2nd and 3rd, around AR 1081 on the 11th and 12th, around AR 1082 on the 20th and 21st and finally at approximately 24°S/204° on the 26th and 27th.
The single Hsx sunspot first seen at end of June, AR 1084 at 18°S/143°, continued its passage across the solar disk until it was last seen on the western limb on the 8th. An Axx sunspot near the eastern limb on the 9th developed into a Dso group by the 10th at 20°N/333° (AR 1087). By the following day small sunspots could be seen between the leader and follower and the total area was an estimated 140 millionths. Observations on the 14th and 15th showed only one penumbral sunspot and a few surrounding sunspots. After this the group began to decay such that only an Axx sunspot remained on the disk on the 18th and this had disappeared by the following day. On the 11th only an Axx sunspot was seen at 21°S/339° (AR 1088).
The day after the decay of AR 1087, AR 1089 appeared around the limb has an Hsx type group. By the 21st it could be seen that the group, at 23°S/202°, was of type Dac comprising several penumbral and other sunspots. Further sunspots had appeared by the 22nd when the group was now of type Eac and it had an area of 260 millionths. Just two penumbral sunspots remained on the 24th although many sunspots were still seen between these. The group decayed as it neared the western limb. Observations on the 28th and 29th also showed an Hsx group at 13°N/81° (AR 1092).
On the 5th a pair of prominences were seen above the NW limb having, presumably, been ejected from the limb. On the 21st a bright small prominence was seen just above the solar equator on the NW limb.
Hα activity during the month was dominated by filaments. On the 2nd, 3rd and 4th a string of filaments were seen in the northern hemisphere which straddled the meridian on the 2nd. On the 3rd when the filament was less fragmented its total length was estimated to be 30°. The majority of this filament disappeared by the 5th. An S shaped filament was seen near AR 1087 on the 10th and 11th. Further smaller prominences were seen throughout the rest of the month although the number steadily reduced (observations made up to the 24th).
Plage was seen around AR 1087 from the 10th to 19th which was quite extensive on the 14th and 15th when the group was near the meridian and quite bright when seen on the 17th. Plage was also seen around AR 1089 on the 19th, 21st and 24th.
The first observation of the month, on the 8th, still showed AR 1092 at 14°N/81° from July as an Hsx sunspot but now nearing the western limb. Two other groups were seen on the disk – AR 1093 at 12°N/353° and AR 1095 at 16°S/3 with both being of type Cso. On the following day AR 1096 of type Bxo had formed near the central meridian. By the 11th AR 1092 had disappeared around the limb but two other small groups had developed on the disk to give a total of 5 groups. The new groups were AR 1097 at 32°N/275° of type Axx and AR 1098 at 15°N/302° of type Bxo. By the 14th only two groups were seen, AR 1093 and a new group, AR 1099, just further towards the north at 18°N/347°. On subsequent days these two groups progressed towards the western limb with just AR 1099 seen on the 16th very close to the limb. AR 1099 reappeared on the 16th and it was also seen on the 17th and 18th together with a further new group of type Axx at 24°S/203° (AR 1100).
No sunspots were seen on the 19th, 20th, 22nd and 23rd while on the 24th AR 1101 of type Hsx was first seen on the eastern limb at 13°N/82° – its appearance changed little for the rest of the month when it had an area of 120 millionths. It was joined by AR 1102 on the 29th at 27°N/103° having formed near the central meridian. It was if type Dao with an area of 60 millionths on the 30th and 31st.
Hydrogen Alpha:None of the prominences seen from 9 observations were particularly striking with the possible exception of one in the shape of a “parasol” seen on the SW limb on the 18th. Filaments were seen on each on the observations with the longest seen on the NE quadrant on the 9th and the most numerous seen on the 17th & 18th. Plage was seen around AR 1093 and 1096 on the 9th, around AR 1098 on the 17th and 18th and around AR 1102 on the 31st.
On the 1st AR 1101 at 13°N/81° and AR 1102 at 27°N/102° were progressing towards the western limb. AR 1101 remained of type Hsx with an area of 130 millionths when it was last seen on the 3rd. Although AR 1102 was of type Cao with an area of 80 millionths on the 1st it decayed such that it was last seen as type Axx on the 3rd. Two new groups formed on the disk on the 2nd – AR 1103 at 26°N/84° of type Bxx and AR 1105 at 19°N/48° of type Cso. AR 1103 was only seen on the 2nd while AR 1105 was last seen on the 7th as an Hsx sunspot near the western limb. No sunspots were seen on the 9th.
AR1106 was first seen on the 11th as an Hsx sunspot near the eastern limb at 19°S/215°. By the 15th it had become type Hax with an area of 70 millionths. Also on the 15th another active area had formed at similar latitude as AR1106 some 13° towards its east at 18°S/202°. This was of type Bxo before becoming type Dso on the 16th, Dao on the 17th and Hax on the 18th. Both this AA and AR 1106 had decayed on the disk by the 21st.
Another southern group appeared around the eastern limb on the 16th – AR 1108 at 29°S/143° of type Dao. On the 21st it had become type Hax with an area of 290 millionths before decaying slightly – it was last seen on the 25th with an area of 180 millionths. AR 1108 also had another trailing active area at a similar latitude – it was first seen on the 17th close to the limb as a single Hsx sunspot at 30°S/129° and last seen on the 21st as an Axx sunspot (it was not seen on the 22nd).
Hydrogen Alpha:Of the prominences seen from 5 observations the most striking was a NE limb spike prominence seen on 21st which had a height of 100,000 km. Many filaments were seen on the 11th especially in the western hemisphere. Plage was seen around AR 1101 on the 1st.
On the 2nd AR 1109 at 21°N/64° from September was now nearing the western limb as a type Dko group with an area of 350 millionths. Another northern group was seen at 23°N/341° of type Axx (AR 1111). The next observation on the 7th had a blank disk as was the case on the 8th and 9th.
On the 10th an Axx group had rotated around the eastern limb at 17°S/202°. By the following day this group, AR1112, had developed into a small Hsx sunspot with an area of 50 millionths. It was of similar appearance on the 12th but by the 17th it had developed into a Dac group comprising several small penumbral sunspots together with other sunspot and the total area was 110 millionths. It had rotated off the disk by the 20th.
Also on the 17th two Hax sunspots were seen in the eastern hemisphere. AR 1113 was at 17°N/140° with an area of 130 millionths and AR 1115 was at 29°S/125° with an area of 190 millionths. Both group remained as single penumbral sunspots as they progressed towards the western limb, although both reduced in size slightly and they were last seen on the 24th. On the 20th an Hsx sunspot, AR1117 at 24°N/63°, was first seen on the eastern limb. By the 23rd this group had developed into type Cso with the appearance of a few small sunspots to the south-east of the penumbral sunspot. The development continued on the 24th with appearance of more sunspots such that it was now of type Dao with an area of 120 millionths. By the 27th, with the group just past the central meridian, there were now four main penumbral sunspots and the total area had become 310 millionths. Just three penumbral sunspots were seen on 30th with the group near the western limb.
Finally onthe 30th a high latitude Axx sunspot was seen close to the eastern limb at 36°N/287° (AR 1120).
On the 10th a combined prominence & filament was seen close to the SE limb. Although filaments were seen on all 5 observations made during the month, the most numerous and longest were seen on the 17th - three long filaments were seen in the western hemisphere, one in the north and the other two in the south. AR 1112 was at the end of one of these filaments and a flare was seen from the start of the observation at 1055 UT until it disappeared at 1113 UT (this was a B6 flare). Plage was seen around AR 1112 on the 10th and 17th.
The observation on the 6th showed two Bxo groups at 15°N/262° (AR 1122) and 19°S /215° (AR 1121). Three other groups were seen on the next observation on the 16th – AR 1124 at 15°N/170° of type Eao with an area of 250 millionths, AR 1125 at 31°S/106° of type Cao with an area of 80 millionths and AR 1127 at 24°N/56° of type Hsx close to the eastern limb. The bipolar group AR 1125 was seen again on the 18th but it was now nearing the western limb. AR 1126 developed into a small Dao group by the 18th while AR 1127 remained of type Hsx with an area of 140 millionths. This latter group was seen again on the 24th and 26th but it was of reduced size. On the 27th a new Axx group, AR 1129, at 25°S/42° had developed on the disk. AR 1130 seen near the central meridian on the 29th at 14°N/327° having also developed on the disk – this group was of type Dao with an area of 120 millionths.
On the 5th there were 3 groups – AR 1132 of type Bxo at 12°N/252°, AR 1131 of type Hhx at high latitude of 31°N/309° and AR 1133 of type Hsx at 15°N/179°. AR 1131 and 1133 were seen again on the 9th when they had areas of 310 and 120 millionths respectively. They were both seen finally on the 11th. Observations on the 17th, 20th and 24th showed blank disks. The final observation of the month on the 26th showed a Bxo group, AR 1137, at 16°N/315°.
Only 2 Hα observations were made during the month. On the 11th an impressive arch prominence was seen on the SE limb – a hedgerow prominence was also seen on the same limb but further towards the equator. A small region of plage was seen around the Hhx sunspot AR 1131. Much smaller prominences were seen on the 26th which were mainly in the northern hemisphere.
Page created on 03 January 2010.