December 17, 2020
Brief Summary of CR 2237
By Kim Hay
ALPO Solar Assistant Coordinator
CR2237 started on November 1, 2020 at 07:21 UT and ended on November 28 at 14:45 UT.
November started off very low in sunspot numbers with AR2780 and AR2781 producing a C class flare on November 8th. This in turn triggered an auroral display in the upper atmosphere for the Northern hemisphere. By the 12th AR2782 produced a C class flare, and the Stereo A satellite was monitoring two UV hotspots on the backside of the sun which were getting close to appearing
On November 18th new Sunspot AR2783 appeared. On November 20th, this spot produced two long B flares in UV. There was a Northern group AR2784 that showed up briefly on November 22nd. Then the next day saw AR2785 (S23E66, Hsx/alpha) and AR2786 (S16E74 Hsx/alpha), and AR2783 (S22W00, Cso/beta) develop trailer spots with B-class activity. AR2784 (N23E08 Bxo/beta) was stable and quiet. A C class flare was reported from AR2785. The Wilson Effect was seen on images by the SDO and Pete Lawrence (UK). It was also captured in images by ALPO observers Theo Ramakers and Frank J. Melillo (see below).
November 25th revealed two small groups rotating into view that were not yet numbered. Space Weather Prediction Centre reported that “AR2785 is 110 millionths and Cso(Beta) while AR2786 is at 800 millionths and Fko (Beta/Gamma)”. The associated auroral display produced the purple glow known as “Steve” (discovered by Canadians 10 years ago), a river of gas with temperatures of 3,000º C passing through the Earth’s magnetosphere faster than 13,000 miles/hour. In an article at spaceweather.com published November 22nd it appears that “Steve” now has green cannon balls under a sequence of vertical pillars dubbed “the green picket fence”.
As CR2237 was drawing to a close AR2786 was growing larger and producing C class flares on November 26th. Two days later an M class flare came from the backside of the sun originating from spots had not rotated into view yet. AR2786 (beta/gamma) was breaking up with light bridges.
So, all in all a very exciting and interesting month for sunspot and Solar activity. We are definitely in Solar Cycle 25!
Thanks to the following Observer’s who submitted their sketches (S) and digital images (D) which are now archived in the A.L.P.O Solar Gallery for CR2237:
- Theo Ramakers [D]
- Howard Eskildsen [D]
- Frank J. Melillo [D]
- Dave Tyler [D]
- Randy Tatum [D]
- Paul Andrew [D]
- Christian Viladrich [D]
- Tony Broxton [S]
- Guilherme Grassmann [D]
- Geert Vandenbuicke [D]
- Monty Leventhal [S]
- David Teske [D,S]
- Rik Hill [D]
- Vlamir da Silva Junio [D]
