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Solar Highlights for November 16


Solar Rotation Nos: 2182 to 2183

Very low levels of sunspot activity were seen this month. There were some high latitude aurorae (however, you had to be somewhere like Alaska to see them) but all caused by coronal holes allowing bursts of the solar wind to buffet the Earth’s magnetic field.

Here are the solar highlights of November 2016 together with a selection of images.

Sunspot summary 

Most of November was quiet with either low, or very low, sunspot activity. It was not until the end of the month, the last two days especially, that we saw a significant rise in the number of sunspots.

1st to 9th November
On the 1st and 2nd only Active Region (AR)2605 was visible. This was a northern hemisphere “pore” (a very small sunspot), of sunspot type: Cro, near the Central Meridian (CM). This sunspot disappeared on the 3rd, leaving the Sun blank, only to reappear in much the same position on the 4th together with AR2606, another tiny Axx type sunspot near the East (E) limb. Both active regions then progressed across the solar disc until the 9th when the Sun was again spotless.

10th to 22nd November
From the 10th onwards we had AR2607, a southern hemisphere sunspot of type Bxo near the W limb, and nearby AR2608, a spot north of the solar equator, also type Bxo. AR2607 developed slightly on the 11th and 12th. AR2608 appeared near the W limb on the 12th on the southern hemisphere and AR2610 then appeared on the 13th, between the E limb and the CM, on the northern hemisphere, sunspot type Cro. We then saw a decline in sunspots as AR2608 and AR2609 disappeared leaving just AR2610, now type Dai. AR2611 briefly appeared on the 18th showed a burst of development but was gone by the 22nd leaving a spotless Sun.

23rd to 30th November
Something was about to appear over the E limb and by the 24th we knew that AR2612 had arrived on the northern hemisphere. This was not a major sunspot but it did grow to a type Cao sunspot by the 28th and was joined by AR2613 on that day. AR2614 appeared on the 29th, this type Cro sunspot was just on the northern hemisphere as did AR2615, near the E limb just south of the equator. It was AR2615 that produced an M-class solar flare (the first for some time) at 17:23 on the 29th. On the last day of November AR2613 had gone but AR2614 and AR2615 remained visible.

Want to know more about the sunspot classification? See our guidance on the Solar Section pages of the SPA website.

SPA Sunspot Mean Daily Frequency (MDF): 1.31 (was 1.73) SPA Relative Sunspot Number: 17.59 (was 24.73)

Prominences, Plage, Filaments and Flares summary

The Sun in H-alpha was quiet for most of November but there some interesting prominences seen early in the month and something of a burst of activity in the last part of the month.

1st to 10th November
There were some small prominences around the solar limb and several dark filaments across the disc. The 7th saw some interesting prominences on the SE and NW limbs. This activity persisted and on the 10th a substantial prominence was seen ejected clear of the S limb. 

11th to 30th November
On the 11th there were two hedgerow type prominence on the N and S limbs. There was a small amount of plage activity too. It was not until the 23rd that we saw substantial prominence activity around the limb again (though we might have missed some of this activity from the 11th to the 20th because of poor weather in the UK. Both the E and W limbs had substantial intricately detailed prominences along them on the 23rd. There was a gradual reduction in their number and extent on the 24th and 25th but by then we were seeing a cluster of filaments to the east and north of sunspot AR2412 too. These filaments seemed to spread across the northern hemisphere by the 27th and we saw another smaller ejected prominence on the W limb that day.    
SPA Prominence Mean Daily Frequency (MDF): 3.60 (was 5.01)

Well done to Brian Gordon-States who observed 23 days in November.  Jonathan Shanklin observed 19 days, Alan Heath 18 days and Michael Fullerton 17 days.

Detailed count records of Active Regions and Relative Sunspot Numbers came from: Brian Gordon-States, Michael Fullerton, Alan Heath, Mick Jenkins, Ian Lee and Jonathan Shanklin.

Images and drawings were supplied by: Mark Beveridge, Carl Bowron, Mick Jenkins, Ian Lee, Cliff Meredith, Julia WIlkinson and Brian Woosnam.

Finally, can I take this opportunity to wish everyone a Merry Christmas and a peaceful Happy New Year.

Geoff Elston


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