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 2020

Activity increased slightly through the presence of three groups including two from the new cycle.  The first of these was an Axx sunspot on the SE quadrant at -35°/358° seen on the 4th (AR 2755).  The next observation on the 9th showed another new cycle group, AR 2756, close to the NW limb at 20°N/18° of type Bxo and comprising three sunspots.  This group was not seen on the following day – the disk was blank as was also the case on the 11th (when faculae was seen on the SW limb).  No sunspots were present on observations made on the 18th, 19th and 21st.  The final observation of the month, on the 28th, show an old cycle group, AR 2757, close to the equator at 2°N/90° comprising a penumbral sunspot of area 90 millionths.

Hydrogen Alpha:
The Sun was observed in Hα on four days.  On the 4th two small prominences were seen together with a region of plage associated with AR 2755.  No features were seen on the 12th, 18th or 19th.

February 2020

Only one sunspot was seen during the month – this was an Axx sunspot AR 2757 on the 1st close to the western limb. The other 12 observations spanning the 5th to 29th revealed blank disks.

Hydrogen Alpha:
The Sun was observed in Hα on three days.  On the 1st plage was seen associated with AR 2757 while on the 8th a filament was seen in the southern hemisphere and on the 29th a filament was seen in the northern hemisphere.

March 2020

Two sunspot groups were seen during the month.  AR 2758 was seen on the 8th and 9th at 30°S/230° as two small sunspots on the 8th and a single sunspot on the 9th (both type Axx).  No drawings were made on the 7th or 10th.  The second group, AR 2759, was seen near the eastern limb on the 31st at 26°N/255° as a single Axx sunspot – faculae were seen following the sunspot.  The other 18 observations made throughout the month including every day from the 21st to 30th were all blank.

Hydrogen Alpha:
Hα activity remained low although a number of prominences were seen towards the end of the month (based on 12 observations). On the 8th, plage was seen associated with AR 2758. For the six observations between the 21st and 26th only a small filament were seen on the 23rd.  On the 29th two small prominences were seen, one prominence on the 30th but three on the 31st together with plage associated with AR 2759.

April 2020

Activity increased slightly during the month through the appearance of four groups, one at the beginning and three at the end of the month. One of these was from the old cycle. AR 2759, first seen in March 31, continued its passage across the solar disk.  On the 1st, 2nd, 3rd it was of type Bxo at 27°N/261° while it was last seen on the 4th as a single Axx sunspot near the central meridian. There were then blank disks until the 25th when AR 2760 was seen at 8°S/306° as an Axx sunspot – it had developed in the disk.  It was of type Bxo on the 26th, Axx on the 27th and Bxo again on the 30th (no observations were made on the 28th and 29th).  AR 2761 at 17°S/329° of type Bxo was seen near the central meridian on the 27th only.  On the 30th AR 2762 of type Axx was seen at 22°N/339° near the western limb.

Hydrogen Alpha:
A few prominences were seen during the month based on 26 observations, including on the 1st with three prominences, a spike prominence on the 2nd, a small loop prominence on the 5th and small prominence on the 15th, 16th and 17th. Plage was seen associated with AR 2759 on the 1st, 4th, 6th and 7th and with AR 2760 on the 26th, 27th and 30th.  Small filaments were seen on the 9th, 21st, 23rd and 25th.

May 2020

No sunspots were observed during the month from 30 observations (the only missed observation was on the 4th).

Hydrogen Alpha:
There was some Hα activity during the month but also some days without any activity (based on 17 observations). Plage was seen associated with AR 2760 on the 2nd. A particularly tall thin spike prominence was seen on the 10th on the NE limb.  A striking elevated arch prominence was seen on the NW limb on the 24th – there appeared to be a gap between the lower part of the prominence and the limb. Smaller spike prominences were seen on the 2nd, 9th, 22nd, 28th and 31st.  Small filaments were seen on the 3rd, 6th and 29th.

June 2020

Three groups were seen during the month, two being from the new cycle. On the 1st only an Axx sunspot was seen near the north east limb at 33°N/163° (AR 2764).  The disk was spotless on the 2nd.  On the next observations on the 5th a Cao group was seen at 22°S/113° with an area of 140 millionths (AR 2765). The follower had developed a penumbra by the 6th to become type Dso before reverting to type Cso on the 7th. It remained of type Cso on the 8th and 9th but with the group past the central meridian, it became type Hsx on the 11th with an area of 90 millionths. It was last seen on the 14th near the eastern limb of type Hrx with nearby faculae. No sunspots were seen for the next 9 observations until the 26th when an Axx sunspot was seen nearing the western limb at 10°N/307° (no AR number). A spotless disk was seen on the next day and on the 28th and 29th.

Hydrogen Alpha:
There was an increase in Hα activity during the month especially associated with AR 2765. On the 1st and 2nd an extensive prominence was seen on the NW limb – on both occasions a gap was seen between the limb and the prominence. On the 1st further smaller prominences were seen further towards the south while on the 2nd plage was seen associated with AR 2764. On the 6th and 7th two areas of filaments were seen – one around AR 2765 and the other further towards the south. Plage was seen within the filaments of AR 2765 on both dates. On the 13th and 14th plage was seen associated with AR 2765. On the 18th a ‘cloud’ prominence was seen on the SW limb as well as small filaments in the northern hemisphere. Small filaments were seen on the 22nd and 23rd. Two prominences were seen on the 28th.

July 2020

As in June, three groups were seen during the month but all were from the new cycle. On the 1st only an Axx sunspot was seen near the south east limb at 23°S/141° (no AR number).  The disk was spotless until the 21st when an Hsx sunspot appeared on the south east limb, AR 2767, at 19°S/198°. On the 23rd with the sunspot further onto the disk it had an area of 100 millionths while on the 26th a following sunspot appeared to make the group type Cao. Thereafter it became type Hax of a similar size and it was last seen on the 31st approaching the western limb.  On the 29th an Axx sunspot was seen near the eastern limb at 25°N/112°, AR 2768. It remained of this type on the next two days and there was an extensive following area of faculae.

Hydrogen Alpha:
Two small prominences were seen on opposite limbs on the 1st and another small prominence was seen on the 15th.  A pillar prominence was seen on the SW limb on the 20th while another tall prominence was seen on the SW limb on the 29th.  Filaments were seen in the northern hemisphere 6th, 7th, 11th and 12th and again on the 31st.  Plage was associated with AR 2767 on the 31st.

August 2020

AR 2767 at 18°S/198° seen during the July continues its progression towards the western limb on the 1st and 2nd, still of type Hsx.  On the 1st only an Axx sunspot was seen just past the central meridian and near the equator at 3°N/143° (no AR number).  No sunspots were seen on the 3rd.  On the 4th, a Cso group appeared near the eastern limb at 23°N/24° – this being AR 2770.  The following pore was present intermittently as the group progressed across the disk. It obtained an area of 80 millionths on the 8th when it was type Hax. On the 10th the penumbra has disappeared to leave two pores that were once the main sunspots umbra. Only one of these was present on the following two days and the group had disappeared by the 13th when it would have still been on the limb.

On the 13th the only group seen was AR 2771 of type Bxo at 18°S/297° in the south-east quadrant. Another blank disk was seen on the next observation on the 17th. Another Bxo group appeared on the disk on the 18th – this being AR 2772 at 19/295 in the north-west quadrant.  It was seen on the next observation on the 20th but not on the 21st.  There were then blank disks for the remainder of the month.

Hydrogen Alpha:
Plage was seen associated with AR 2770 for observations on the 4th, 6th, 7th, 9th-11th.  Of particular interest was a B.6 flare seen within AR 2770 on the 11th from 17:00 – 17:20 UT. The maximum of the flare was at 16:59 UT and indeed the flare was at its brightest at the start of the observing period and was not different in appearance to other plage within the group at the end of the observing period.  Small prominences and filaments were seen on a few of the 15 observing days.

September 2020

From 24 observations made during the month only one showed any sunspots.  This was on the 28th when a pair of nearby sunspots of type Axx were seen at 20°S/91° (no AR number).

Hydrogen Alpha:
Activity during the month remained low. Small filaments were seen on some of the 16 observations – for example three were seen on the 2nd in the NW quadrant.  Small prominences were seen on most days including the same prominence on the SE limb on the 20th, 21st and 22nd.  Also on the 20th several prominences were seen on the NW limb. On the 24th, plage was seen near the eastern limb associated with AR 2773 – this was also seen on the 28th and 29th. A smaller region of plage was seen in the S hemisphere on the 28th and 29th.

October 2020

There was a substantial increase in activity during the latter half of the month through the appearance of the most complex group so far in cycle 25. Five new cycle groups were seen, all being the southern hemisphere.

The first four observations of the month on the 1st, 5th to 7th all showed blank disks.  On 9th two groups were seen either side of the central meridian: AR 2774 at 23°S/309° of type Axx and AR 2775 at 23°S/273° of type Bxo.  The first of these groups was not seen on the 10th while AR 2775 was still of the same type before becoming type Cro on the 11th when several sunspots were seen within the group.  AR 2775 was not seen on the 14th – another blank disk observation although faculae was seen on the east, north-west and south-west limbs.

On the 17th a Cao group was in the south-east quadrant at 12°S/161°. On the 19th the group, AR 2776, was near the central meridian and a small number of followers were seen.  These had disappeared by the following day to give an Hsx sunspot and AR 2776 remained of this type as it progressed towards the western limb – it had an area of 140 millionths on the 23rd and it was last seen on the 25th. Also on the 25th a Bxo group appeared near the central meridian at 19°S/86°. By the following day, this group – AR 2778 – developed into a Dso group with several small penumbral sunspots throughout the group. It had an area of 140 millionths. Further development took place by the 19th when substantial leading and following penumbral sunspots were seen and the group became type Dac with an area of 370 millionths. Only a single Hax sunspot was seen on the 31st when this group was close to the western limb. Also on the 31st another group was seen to the north of AR 2778; this was AR 2779 of type Bxo at 12°S/75°.

A revised and more accurate method is now being used to calculate sunspot areas. As described in paper https://doi.org/10.1093/mnras/staa2007, a pixel mask approach is now being used from scanned disk drawings rather than using a square grid overlay on the paper version of the drawings.  The areas will now generally be larger previously measured and than those derived by NOAA (as also described in the paper) and more consistent with other professional sunspot area databases.

Hydrogen Alpha:
Prominences were seen on all 7 observations made during the month – the most spectacular being a series of nearby spike prominences on the 22nd near the E limb. A broken filament was seen in the NW on the 25th and 26th. Plage was seen in the NE quadrant on the 1st (not associated with any group) and on the 25th around the Bxo group AR 2778. 

November 2020

December 2020

Page created on 11 November 2020.