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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.
Only one group was seen during the month: AR 1010 on the 11th at 19°N/21° and of type Cri with an area of 20 millionths. Seven sunspots were seen. No further observations were possible until the 17th when this group was not visible. The other nine observations made during the month showed spotless disks. On the 17th two bright regions of faculae were visible, one on the western limb at 22°N/23° (AR 1010) and the other on the eastern limb at 31°N/256°. By the following day, the western faculae had disappeared having rotated off the disk while the eastern faculae was still visible but much fainter. Hydrogen
Alpha: The most prominent prominence seen from four observations was of a small hedgerow type on the NE limb on the 11th. Also on the 11th plage was seen around AR 1010 while on the 17th and 18th plage was seen in the NE quadrant at approximate location 27°N/264°.
AR 1012 was seen near the eastern limb on the 11th and 12th as a single Axx sunspot at 5°S/278° (and so from the old solar cycle). It has disappeared by the 13th. The other 10 observations made during the month showed spotless disks. Hydrogen
Alpha: None of the prominences seen from seven observations were particularly striking as they were all quite small. A small filament was seen on the 7th in the NW quadrant.
An Axx group comprising two sunspots was seen near the central meridian at 4°S/34° on the 6th. On the following day, this group, AR 1014, had reduced to a single sunspot and it had disappeared by the 8th. The other 17 observations made during the month showed spotless disks. Hydrogen
Alpha: The most significant prominences seen were on the 2nd when a ‘cloud’ shaped prominence was seen just above the NW limb; on the 22nd a three ‘spike’ prominences on the NW limb and on the 30th when another ‘cloud’ prominence was seen also above the NW limb. Small filaments were seen on the 2nd (NE quadrant), 8th (NE quadrant) and 15th (SE quadrant).
A single Axx spot was seen near the western limb on the 21st only. This group, AR 1015, was at 22°N/212° and hence from the new solar cycle. The other 20 observations made during the month showed spotless disks. Hydrogen
Alpha: Most prominences observed during the month were small. On exceptions was on the 22nd on and 24th. On the 22nd a ‘cigar’ shaped prominence was seen just above and lying just above the NE limb – it was connected to the limb by thin strands of hydrogen. On the 24th a moderately sized arch type prominence was seen on the SW limb – it was not seen on the following day. Unusually there no prominences were seen on the 20th and 21st. Plage was observed around AR 1015 on the 21st (like the white light sunspot it was not seen on the 20th and 22nd). A filament was seen on the 1st on the NE quadrant together with very small filaments on the 18th, 19th and 29th.
On the 15th, a single curious sunspot was seen nearing the central meridian. It had the appearance of a penumbral Hax sunspot but without any umbra! This was AR 1017 at 19°N/184°. By the following day two sunspots without any penumbra were seen (type Bxo) while on the 17th three sunspots were seen (again type Bxo). A second group was seen on the 31st as a single Axx spot at 25°N/295° (AR 1019). Hydrogen
Alpha: Hα activity was higher during the month compared to the last few months. On the 2nd a striking prominence was seen on the NW limb but it was not seen on the following day. On the 8th, a small bright and rapidly changing region of hydrogen was seen close to the NW limb. The number of prominences seen reduced towards the middle of the month (none seen on the 10th) before increasing again towards the end of the month. On the 26th, there was a nice prominence on the SE limb. On the 10th two filaments were seen, one towards the northern hemisphere pole and the other close to AR 1017. This was also the case on the 11th although there was a third filament close to the eastern limb. On the 12th only the filament close to AR 1017 remained. Single filaments were seen on the 21st, 24th and 25th while two were seen on the 29th. Plage was seen around AR 1017 on the 10th to 12th, 15th and 17th and around AR 1019 on the 31st.
AR 1019 seen at the end of May continued to develop at the start of the month. By the 2nd this group was of type Dao at N°25/295° with an area of 90 millionths. By the 4th, however, it had decayed back into a Bxo group. It was not seen on the next observation on the 7th. There were spotless disks until the 23rd when a Bxo group was seen at 23°S/19° (AR 1023). It was seen again on the 24th with more small sunspots but it had disappeared by the 25th. The disk remained spotless for the rest of the month. Hydrogen
Alpha: There were no striking prominences observed during the month – the largest prominences seen were on the 1st & 2nd when a hedgerow type was on the NE limb and again on the 25th when another hedgerow type was seen on the NE limb. No filaments were observed during the 9 observations made during the month. Plage was seen around AR 1019 on the 1st & 2nd and AR 1023 on the 23rd.
On the 4th a small active region developed on the disk near the central meridian (no sunspots were seen on the 3rd). This group, AR 1024, was located at 25°S/248° and of type Bxo. By the 5th it has developed into a Dac group with several small penumbral spots seen throughout its length – the total area was 130 millionths. On the following day, there were less spots in the middle portion of the group. By the next observation on the 9th, the group was still of type Dsc while on the 10th with the group nearing the western limb, it comprised of just two small penumbral spots although it had elongated into a type Eso type group. The group was not seen on the 11th. On the 23rd only a small old cycle Axx sunspot was seen near the central meridian at 5°S/5°. Hydrogen
Alpha: Although prominences were seen on each of the 15 observing days, none were particularly striking. On the 3rd an arch prominence was seen on the SW limb and a hedgerow prominence on the NE limb. On the 31st an unusual ‘apple tree’ shaped prominence was seen on the SW limb which had a bright thin trunk and a fainter diffuse canopy. Filaments were seen at the start and end of the month only (1st and 30th). Plage seen on the 4th, 5th, 6th and 9th was associated with AR 1024. The appearance of this AR in Hα was quite changeable in terms of filaments and plage, especially on the 4th.
No sunspots were seen from the 19 observations made during the first 30 days of the month. On the 31st AR 1025 was seen at 1540 UT as a two-sunspot Bxo group at 18°N/169°. This group was not visible earlier in the same day, at 1020 UT. Hydrogen
Alpha: During the first half of the month, the prominences seen were not particularly large although six were seen on the 11th. A similar number were seen on the 23rd but several of these, on the E limb, were quite interesting and included a tall spike type and two arch types. Curiously, only one eastern prominence was seen on the following day. The number of prominences increased again towards the end of the month. On the 29th a particularly tall prominence was seen on the NE limb – it had a reasonably bright spike with a much fainter curved prominence attached to the top of the spike – its total height was estimated to be almost 4’ (160,000km). Also on the same day, on the SE limb an anvil shaped prominence was seen with a faint straight piece of hydrogen between one end of the anvil to another prominence further north. Small filaments were seen on the 3rd, 8th and 23rd while another filament was seen on consecutive days in the south between the 27th and 29th.
The 13 observations between the 2nd to 20th all showed blank disks. On the 21st a Hrx spot was seen close to the eastern limb at 29°S/220° together with a bright region of faculae. On the next day this sunspot, AR 1026, was seen as being of type Hsx – this was also the case on the 24th when its area was estimated to be 60 millionths. It decayed by the 25th when it was seen as an Axx sunspot and it was no longer visible on the 26th. Although no further sunspots were seen, an extensive area of faculae was visible as this active region progressed towards the western limb. On the 22nd, a Bxo group at 24°N/241° had developed on the disk. By the 24th AR 1027 had grown into a Dso group with an area of 60 millionths. By the 26th, with the group near the central meridian, the leading spot had lost its umbra. By the following day only one sunspot was seen while on the 29th AR 1027 was seen as an Axx group nearing the western limb. Hydrogen
Alpha:
October
2009
The 11 observations between the 2nd to 22nd all showed blank disks. By the final observation of the month, on the 23rd, a Bxo group had formed on the disk at 15°N/211° (AR 1029). Hydrogen
Alpha: From the 4 Hα observations made during the month, the most striking prominence was seen on the 4th on the NW limb. This was a hedgerow type prominence where changes could be seen within the span of a few minutes when imaged. The other three observations showed only small prominences.
Four northern hemisphere sunspots groups were seen during the month but all were small. On the 9th AR 1030 was seen at 25°N/47° as a Bxo group. On the 15th and 16th a single Axx spot was seen at 29°N/259° (AR 1031) – this group had disappeared by the following day (17th). Finally on the 19th two groups were seen – one of type Axx at 27°N/236° (no AR number) and the other of type Bxo at 19°N/193° (AR 1033). Hydrogen
Alpha: On the 15th a bright arch type prominence was seen on the NE limb together with a fainter prominence towards the north - changes within the bright prominence could be seen within the span of a few minutes. Another more diffuse arch prominence was seen on the 28th on the NW limb. Two faint filaments were seen near the SW limb on the 28th.
Observations on the 4th, 5th and 6th showed spotless disks. The next observation, on the 12th, showed a Bxo group at 20°N/255° (AR 1034). This small group was seen on each of the next 3 days but only as of type Bxo or Axx. On the 14th AR 1035 had formed on the disk to the NE of AR 1034 at 32°N/247° – this was of type Dso. More sunspots had appeared within this group by the next day (15th). By the next observation on the 18th the group had developed further to be of type Eao with an area of 250 millionths. The appearance of AR 1035 changed little as it neared the western limb on the 19th and 20th. A short-lived single Axx sunspot was seen on the 19th only near the eastern limb at 17°N/138° (AR 1037). On the 20th another group had developed on the disk, this time in the southern hemisphere – it was of type Bxo at 26°S/210° (AR 1036). It was not seen on the next observation on the 25th when the disk was again spotless. On the 26th, a Bxo group was seen near the SE limb at 26°S/56° (AR 1039). By the 27th it had formed into a Dso group with an area of 70 millionths. It was of a similar appearance on the final observation of the month on the 28th. Hydrogen
Alpha: A nice pillar prominence was seen on the NW limb on the 5th and 6th. A hedgerow prominence was seen in a similar location on the 12th together with a fine spike prominence in the NE limb. Other prominences seen four other dates later in the month were all small. Plage was seen around AR 1034 on the 12th while four regions of plage were seen on the 19th and 20th plus small filaments near AR 1035 on the 19th. Plage was seen around AR 1039 on the 28th when a filament was seen also near the NW limb.
Page created on 21 December 2008. |
