Solar Rotation Nos: 2238 to 2239
There was a slight rise in sunspot activity with some small sunspots to be seen throughout the month.
Here are the solar highlights for December 2020 together with a selection of images.
Sunspots
The southern hemisphere of the Sun continues to produce more sunspot activity than the north, continuing a trend seen in the past few months. This can be seen in the latitude positions of the sunspot Active Regions.
AR2785 at latitude -23° and AR2786 at -16°, both appeared in late November, and in early December were seen heading towards the west solar limb. While the follower spots of AR2786 had faded, the leader was still very noticeable. Both went over the west limb around the 6th.
AR2787 a tiny Axx spot that appeared near the east limb on the 30th November at +29°. It was seen on the 1st but had disappeared the following day.
AR2788 another type Axx sunspot, appeared at -29° on the last day of November but was gone by the 2nd.
AR2790 was type Cso and was first seen just emerging from the east limb on the 1st at latitude -23°. This small cluster of sunspots was solar flare active producing a several C-class flares. It seemed to fade as it headed west and went over the west limb on the 13th.
AR2791 appeared on the 6th at -16°, this was type Bxo initially before fading to type Axx and disappearing on the 9th.
AR2792 came over the east limb on the 14th at -23°. This was another small type Bxo that lasted until the 17th. It seems to have produced a C-class flare on the 15th.
There was a total eclipse of the Sun on the 14th but it was only visible from Chile and Argentina. Totality was a brief 90 seconds.
AR2793 came over the east limb on the 15th at latitude -16°. This was a small type Axx sunspot that developed a little by the 16th but then seemed to fade thereafter before disappearing on the 18th.
The Sun was briefly spotless on the 19th and 20th.
AR2794 was a single Hsx sunspot that appeared over east limb at -17° on the 21st. It remained unchanged and was still visible up to the end of the month.
AR2795 came into view also at -17° on the 24th as a leader/follower pair type Cro sunspot. It developed to type Dao over the Christmas period before starting to fade but was still visible nearing the west limb by the end of December.
SPA Sunspot Mean Daily Frequency: 1.72 (was 1.58)
SPA Relative Sunspot Number: 21.37 (was 21.74)
Solar Prominences, Plage, Filaments and Flares
Cloudy weather and low Sun had an impact on observations throughout December. Despite these limitations some impressive prominences and filaments were seen.
There were some lovely intricate prominences along the southeast and southwest limbs on the 2nd.
The 3rd saw two detached prominences on the northwest and southwest limbs as well as an arch-type prominence on the southwest limb. A much larger arch-type prominence appeared on the southwest limb on the 7th. Three separate prominences were seen on the northwest, southeast and southwest limbs on the 15th. More impressive prominences were seen on the 17th.
Three intricate-looking prominences were visible on the west limb on Christmas Eve. By the end of December there were more impressive looking prominences along the southeast and southwest limbs.
There were numerous small dark filaments and bright areas of plage around AR2785, AR2786 and AR2790 on the 2nd. Quite extensive filaments were visible between AR2790 and the west limb on the 7th. AR 2792 and AR2793 had bright plage around them on the 15th. Bright plage were visible around AR2794 stretching towards the southeast limb on the 22nd. By Christmas Eve bright areas of plage were seen around AR2794 and AR2795 as they moved away from the southeast limb. By the month-end filaments and plage were still visible around AR2794 and AR2795 as they crossed the centre line of Sun’s disc and a cluster of filaments were seen not far from the southeast limb.
SPA Prominence Mean Daily Frequency: 5.67 (was 2.89)
Congratulations to Brian Gordon-States who observed 21 days and to Jonathan Shanklin on 20 days and Brendan Shaw on 19 days.
Detailed count records of Active Regions and Relative Sunspot Numbers came from: Michael Fullerton, Brian Gordon-States, Ian Lee, Jonathan Shanklin, Brendan Shaw and Bob Steele.
Images and drawings were supplied by: Carl Bowron, John Fathers, Mick Jenkins, Ian Lee, Cliff Meredith and Keith Moseley.