Solar Rotation Nos: 2233 to 2234
New Sunspot Cycle No. 25 sunspots are now appearing in increasing numbers and while small and short-lived they seem to becoming more established now than before.
Here are the solar highlights for August 2020 together with a selection of images.
Sunspots
There was a burst of sunspot activity in the first half of August with small, mainly short-lived sunspots appearing mostly, but not exclusively, on the northern hemisphere.
AR2767 was still visible as the month began, having appeared in mid-July, at latitude -21° but was by now nearing the west solar limb. It was sunspot type Hsx and remained so until the 4th when AR2767 went over the west limb. This was a Cycle 25 sunspot.
AR2768 was also visible, having appeared in late July, just by the east limb at latitude +26°, type Bxo. This sunspot only lasted another couple of days, fading from view by the 3rd. This too was a Cycle 25 sunspot.
AR2769 appeared near the east limb on the 1st. This tiny type Axx sunspot, at latitude +26°, of Cycle 25, was relatively short-lived lasting until the 5th.
AR2770 came over the east limb on the 4th at latitude +21°. Initially, a type Hsx type sunspot (again Cycle 25) it developed quickly to a type Cso sunspot containing 2 spots on the 5th then 3 spots on the 6th and 4 spots by the 7th. A minor C-class solar flare took place in the early hours of the 8th (therefore during the night here in the UK) seemed to mark the peak activity of AR2770. A ‘light-bridge’ was seen dividing the main sunspot on the 9th but thereafter AR2770 began to fade and disappearing by the 14th.
AR2771 appeared on the 13th, of type Bxo, consisting of 3 spots. Despite the fairly low latitude of -18°, I understand that it was a Cycle 25 sunspot. It was short-lived disappearing by the 15th.
The Sun was spotless from the 15th until the 18th.
AR2772 popped-up near the west limb on the 19th. This consisted of 2 spots and was type Bxo and despite the somewhat low latitude of +18° was another Cycle 25 sunspot. AR2772 went over the west limb a couple of days later.
The Sun was spotless from the 22nd to the 31st.
SPA Sunspot Mean Daily Frequency: 0.62 (was 0.43)
SPA Relative Sunspot Number: 7.86 (was 4.61)
Solar Prominences, Plage, Filaments and Flares
There were several interesting prominences this month, particularly the filaprom on the west limb on the 7th and the prominences on the east and west limbs on the 8th to 10th and the 12th. The 13th saw prominences dotted around the solar limb and the 14th saw a low hedgerow type on the northwest limb. A detached prominence was seen hovering above the north limb on the 15th. Prominence activity seemed to decrease slightly until the 30th and the 31st.
There were a number of filaments and plages seen with the sunspots crossing the Sun throughout the month but some were seen on their own, particularly a long dark southern hemisphere filament on the 3rd that was seen split apart by the 6th, and several areas of plage that on the northern hemisphere where no sunspots developed.
SPA Prominence Mean Daily Frequency: 1.32 (was 0.97)
Congratulations to Jonathan Shanklin who observed 30 days in August. Brian Gordon-States, Alan Heath and were a day behind on 29 days each and Michael Fullerton on 26 days.
Well done to Brian Gordon-States who clocked-up 103 consecutive days of solar observations throughout the Summer months before he was clouded-out in mid-August.
Detailed count records of Active Regions and Relative Sunspot Numbers came from: John Chapman-Smith, Brian Gordon-States, Michael Fullerton, Mick Jenkins, Ian Lee, Lee Macdonald and Bob Steele.
Images and drawings were supplied by: Paul Brierley, Carl Bowron, Ian Lee and Cliff Meredith.