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.
The dominant group from the 4th was of type Dkc at 10°S/75° with an area of 770 millionths. It comprised an irregular leading penumbral spot with several umbrae within it and a few small penumbral spots following. When next seen on the 11th, it had reduced in size to 440 millionths with just two penumbral spots and two other spots. On the 13th, an irregularly shaped penumbral spot was seen near the western limb.
Also on the 13th an Eac group was seen near the eastern limb at 12°S/285°. On the 17th, it had two penumbral spots at the leading and following positions with several spots between - its total area was 280 millionths. By the following day it had grown slightly to 350 millionths to become the second largest group seen during the month. This group was last seen on the 24th as a single Hsx spot near the western limb.
No spots were seen on the 27th and 28th while two southern groups were seen on the 29th.
A small Eac group was seen near the eastern limb on the 1st. On the 4th this group, at 13°N/47° had an area of just 100 millionths with three penumbral spots and several spots between the leader and the follower. By the 7th, the number of spots had increased to give the appearance of an elongated group without any significant penumbral spots (as these were quite small). The number of spots within this group reduced as it progressed towards the western limb.
An interesting group was initially seen on the 4th at 7°S/26° as a Dai group with an area of 100 millionths. The size of the leader and follower spots had increased by the 7th to give an area of 230 millionths. By the following day, both the leader and follower spots were of similar size with several other spot around these. The group now had a classical bipolar group appearance. What was now evident was that the follower penumbral spot was much closer to the equator than the leader penumbral spot. The group inclination was such that the leader was at 8°S/29° while the follower was at 4°S/24°. The group had a similar appearance on the 9th although the area had reduced from 350 to 240 millionths.
The largest group seen during the month was first seen on the 21st as a Dso group at 14°N/162° with an area of 70 millionths. By the 23rd, it was now 290 millionths in size with the leader penumbral spot being the largest spot in the group. Growth continued such that on the 25th, with the group just post the central meridian, its area was 400 millionths. Now the leader part of the group comprised two penumbral spots while the single follower penumbral spot was the largest of the group. By the following day, the group had changed appearance quite substantially. Now a region of penumbra was seen from the leader to the follower parts of the group together with two smaller penumbral spots. Many umbrae were seen within the main penumbra. The total area was 620 millionths and the group was of type Ekc. When next seen on the 29th, the group had decayed into several penumbral spots and the group was now close to the western limb.
The largest group seen during the month was near the eastern limb on the 7th, being of type Fkc at 13°S/302°. It comprised of a main leader penumbral spot and two smaller penumbral spots at the following part of the group. On the 9th, it had an area of 760 millionths and was of a similar appearance to the 7th. By the 11th, however, the main leader spot had become much more irregular and more elongated with several umbrae. The total group area had reduced slightly to 620 millionths. The few spots that had existed between the leader and follower penumbral spots had disappeared. The main spot had decayed substantially by the 13th when two symmetrical penumbral spots and a smaller irregular penumbral spot were seen; the total area of the group was now 300 millionths. When last seen near the western limb on the 17th, two small penumbral spots were all that remained of the group. By contrast, the observations of the 7th, 9th, 11th showed no northern hemisphere groups.
A symmetrical penumbral spot was seen on the equator on the 21st, 22nd and 26th at 0°/151°. On the latter two dates, this spot was accompanied by a couple of small spots to give the group a classification of Cso (on the 21st it was of type Hsx).
During the first three weeks of the month, the number of groups seen was quite low at between 3 and 5. On the 26th, a total of 8 groups were seen, split equally between the northern and southern hemispheres. One of these groups was if type Dko at 14°N/55° towards the eastern limb which comprised of an irregular leading penumbral spot and a much smaller follower spot. When next seen on the 29th, the appearance of the group had changed to a single much more symmetrically shaped leading penumbral spot and numerous spots towards the north and east. Thus the group had become type Cai and its area was 200 millionths. The surrounding spots, along with the single penumbral spot were still present on the 30th.
As in recent months, the majority of the activity was in the southern hemisphere. During the month a maximum of 2 groups on any day were seen in the northern hemisphere while in the south a maximum of 4 groups on any day were seen.
Amongst the four groups seen on the 3rd was a Hax spot on the central meridian at 13°S/11° with an area of 200 millionths. This group was seen on the 30th March as a Dao type. By the 4th, the group had become type Dao following the re-appearance of following spots, although the total area had reduced to 140 millionths. The following penumbral spot had disappeared by the 6th to leave a Cao group. On the 6th, 11th and 12th no northern spots were seen.
Activity remained low until the 19th. Of the six groups seen, two were of a similar latitude and were separated by about 20° in longitude. The first of these was a Dsc group at 5°S/129° with an area of 70 millionths. As this neared the central meridian, on the 22nd, it decayed to a Cao group with an area of 30 millionths. It then decayed further and was last seen as an Axx group on the 24th. The second group was of a Dac type on the 19th at 8°S/110° with an area of 190 millionths. By the 20th it had grown to 290 millionths to become the largest group seen during the month. The leading part of the group had the main penumbral spot while the following part had a small penumbral spot and several other spots. On the 22nd, the following penumbral spot had decayed to leave a Cai group. As the group passed the central meridian on the 23rd and towards the western limb, the number of following spots reduced such that only a Hax spot was seen on the 25th to 27th.
The northern hemisphere was spotless again on the 22nd and 23rd. The last observation of the month, on the 27th, showed 2 groups with 1 in each each hemisphere: a Dao group at 14°N/47° with an area of 110 millionths and the aforementioned Hax spot at 7°S/115°.
As in recent months, the majority of the activity was in the southern hemisphere - indeed no northern hemisphere spots were seen until the 14th. Up to the 10th, the number of southern groups seen were either 2 or 3. On the 10th a Cao group was seen towards the eastern limb, with a single asymmetric penumbral spot and a single following spot. By the 13th, several small penumbral spots had developed to make this group, at 2°S/176°, type Dac. It had an area of 160 millionths. By the following day one of the following penumbral spots had grown. On the 15th this growth continued as had a penumbral spot towards the leading part of the group to give a total area of 400 millionths. With the group just past the central meridian, the group had decayed slightly on the 16th including a reduction in the number of spots within the group. The decay continued as it neared the western limb such that on the 21st just an Hsx spot remained.
Another medium sized group was first seen on the 20th as an Hsx spot on the eastern limb. With the group fully on the solar disk on the 21st, at 11°S/39°, the group was of type Dac with an area of 210 millionths. On the 22nd many small spots were seen within the group with the main penumbral spot being in the middle of the group; the group was now of type Dkc with an area of 330 millionths. The appearance of the main penumbral spot had changed by the 23rd but there were still many small spots within the group. The next observation on the 31st showed just an Hsx spot close to the western limb.
Activity until the 13th was very low, especially in the northern hemisphere where, at most, one group was seen. In addition, the maximum number of southern hemisphere groups seen during the same period was just three.
On the 13th, a Cso group was seen near the eastern limb - when seen on the 14th a following penumbral spot had rotated onto the disk to make the group type Eao at 12°N/75°. As this group rotated further onto the disk, it could be seen that the following penumbral spot was the largest of the group. On the 16th, the group had an area of 350 millionths. When next seen on the 19th, the leading penumbral spot dominated with just a small following penumbral spot and no spots in between. On subsequent days, the following part decayed and it had disappeared altogether by the 22nd. During this period, the leading spot also started to decay such that on the 25th, only an Hsx spot was seen close to the western limb.
The largest group of the month first appeared around the eastern limb as an Hsx spot on the 14th. On the 15th several following penumbral spots had rotated onto the disk and on the 16th it was classified as type Fac. When next seen on the 19th, the group, at 9°S/57°, had many more spots but only three had penumbra. By the 20th, a few more penumbral spots were seen and the group's total area was 550 millionths: the group now crossed the central meridian. The appearance of the group changed little when seen on the 21st and 22nd. However when next seen on the 24th, many of the spots within the group had disappeared. The reduction in the number of spots continued as the group neared the western limb. On the 27th only a single penumbral spot was seen on the western limb.
Activity up to the observation on the 10th was very low - on the 5th only two spots were seen in the northern hemisphere. Between the 8th and 10th 4 out of the 5 group seen had developed on the disk. The group that was present on the 8th was the largest of the 5 groups being of type Dac at 6°S/125° with and area of 160 millionths. On the 13th, an Eac group was seen close to the eastern limb at 9°S/45° . As it moved further away from the limb, it could be seen that the group comprised several irregular penumbral spots throughout the group together with several other spots. On the 16th it attained its maximum area of 400 millionths. After this date it started to decay: to 230 millionths on the 19th when the main spot was the leading one and to 70 millionths on the 22nd when the group was of type Csi. It was also seen on the 23rd as an Hsx spot close to the western limb.
On the 16th an Hhx spot was seen on the eastern limb. On the 17th several following spots were seen. On the 19th the group, at 9°N/345°, type Fkc and area 1740 millionths, was fully on the disk. The largest spot was still the leading one - two following penumbral spots were also seen. By the 22nd the shape of the leading penumbral spot had changed with a separate penumbral spot to the north and, by the 23rd, a new leading penumbral spot that had separated from what was the leading penumbral spot. The total area of this group had increased slightly on the 23rd to 1840 millionths. This group was last seen close to the western limb on the 29th.
The large sunspot group from last month was seen on its next rotation on the 21st as a much smaller Dki group at 8°N/349° with an area of 340 millionths. The group consisted of two penumbral spots, with the follower being the larger, and several other spots. By the 23rd just the two penumbral spots were seen. This group was last seen on the 25th close to the western limb. Towards the end of the month the number of groups and spots reduced such that on the 31st just one northern hemisphere Hsx spot was seen near the western limb.
On the 1st only a single Hsx spot was seen on the disk close to the eastern limb at 11°S/96°. It appeared as a slightly larger Hhx spot between the 3rd and 5th with an area of 280 millionths on the 3rd. When next seen on the 11th and 12th attendant spots had appeared to make the group type Cso. It was last seen on the 13th on the western limb as an Hsx spot again. The number of southern groups increased from the 1st such that on the 5th four were seen. However, the absence of northern hemisphere spots continued until the 5th when an Axx spot was just to the north of the solar equator at 0°N/163°.
The large group from July returned on the 10th, for a second time, as a Dac group at 5°N/348°. On the 13th, for example, the group comprised several penumbral spots with many other spots within and surrounding these and it has an area of 280 millionths. The group had a similar appearance as it crossed the central meridian on the 15th but by the next observation on the 18th it had decayed to a Cso group with a total of 5 spots and an area of just 40 millionths. It was seen as a Hsx spot close to the western limb on the 21st.
Another single eastern limb Hsx spot was seen on the 15th. When next seen on the 18th this was a Dso group at 12°S/272° with an area of 440 millionths. The leader was the larger of the two penumbral spots while the follower was more irregularly shaped. By the 19th the follower had split into several small penumbral spots but the group's total area had remained the same. By the 21st, however, the number of following spots had reduced such that the total area was now 330 millionths. When last seen on the 24th just one follower remained while the symmetric leader had stayed the same during its passage across the solar disk. The northern hemisphere was spotless again on the 23rd and 24th.
There was quite a contract in activity during the month with low activity during the first half of the month and moderately high activity during the second half. Between the 1st and 7th, two small southern groups were present and on the 4th only a northern group was seen. Thus on the 1st, 2nd, 6th and 7th no northern groups were seen. The largest of the groups seen during this period was an Hsx spot at 8°S/141° which had an area of 80 millionths on the 4th. On the 10th no spots were seen in either hemisphere.
No northern spots were seen on the next observation on the 18th but a string of 5 groups were seen stretching from the central meridian towards the eastern limb. The largest of these was of type Dai at 11°S/276° which had an area of 150 millionths. On the 21st, this group had developed to type Eac with a slightly larger area of 170 millionths. On this date 2 northern groups had appeared around the eastern limb. One of these was a compact Hax spot which became an Eac group at 12°N/176° by the 24th with an area of 270 millionths when it comprised several irregular penumbral spots spread through the group together with other spots. When next seen on the 28th, this group had decayed to type Dac while on the 31st it was seen as an Hsx spot near the western limb.
On the 24th an Hsx spot was seen on the solar equator at 0°/138°. When seen next on the 28th it was an Hax spot with an area of 60 millionths and on the 30th and 31st several surrounding spots were present to make the group type Cso. Activity had increased again by the 28th with a total of 9 groups seen, 6 being in the northern hemisphere. The only group near the eastern limb was of type Esc at 15°S/78°. By the 30th this bipolar group had an area of 580 millionths which increased to 740 millionths on the 31st when it was of type Eac. Between the 30th and 31st, a larger irregular penumbral spot had developed between the almost equally sized leader and follower penumbral spots. Several other smaller penumbral and other spots were also seen within the group.
On the 4th, the Eac group seen at the end of October at 15°S/75° was now of type Fkc with a total area of 520 millionths. The leading part of the group was an irregular penumbral spot while the following part comprised many small penumbral spots. Also on the disk was a Dko group at 9°N/27° with an area of 620 millionths. This group comprised two penumbral spots and a number of other smaller spots. The follower spot was much larger than the leader and had many umbrae within it. When next seen on the 12th just a small Hsx spot was observed close to the western limb.
Just past the central meridian on the 12th was a Bxo group at 5°N/313° . By the following day two small penumbral spots had appeared to make the group type Dsi. Many other spots had also developed throughout the group. Larger penumbral spots had developed by the 14th while by the 16th the group was bipolar in form. This group had rotated off the solar disk by the next observation on the 19th.
Observations on the 19th and 30th showed 4 and 3 group respectively but all were small in size.
The largest group seen during the month was of type Csi at 9°S/128° on the 20th with an area of just 220 millionths. This group was first seen on the 18th as an Hsx spot near the eastern limb. On the 19th and 20th several following spots appeared. By the 23rd, the main penumbral spot had become asymmetrical with two smaller following penumbral spots. The total area of the group has reduced to 140 millionths. On the 25th, the only penumbral spot was the leading one which became symmetrical again. By the 27th all following spots had disappeared to leave a Hsx spot. However, on the 28th, with the group nearing the western limb, two penumbral spots had appeared in the following position.
Of the other 6 groups seen during the month, all except one were either of type Axx or Bxo. The exception was a Dsc group at 6°N/336° and on the eastern limb on the 28th. No northern hemisphere sunspots were seen on the 9th, 18th, 20th, 23rd and 25th to 27th while the southern hemisphere was devoid of sunspots on the 11th.
Last updated on 11 January 2005.