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Solar Highlights for November 15

 

Solar Rotation Nos: 2170 to 2171

The continual poor weather and low-Sun have prevented many from making observations. Despite this we did receive quite a few images and sunspot counts for November. These showed there was a further decline in the number of sunspots and is to be expected. There were some interesting sunspot groups but on the whole most were small in nature. There have been several high-latitude aurorae throughout the month but these have been caused by the solar corona and the generally disturbed nature of the solar wind.

Here are the highlights for November 2015 together with a small selection of images.

SUNSPOT SUMMARY

The beginning of the month saw the long complex sunspot group (A)ctive (R)egion 2443 clearly visible near the (E)astern limb of the Sun. It had grown considerably since its appearance over the solar limb in late October Alan Heath reports just being able to see it with the protected naked eye on the 1st. AR2443 was now active with a complex magnetic field so flares seemed likely. On the 2nd it was classed as a type Fkc and as an example was vastly larger than the Earth. 

Nearer to the (W)est limb at this time was AR2445, this was type Dai sunspot on the 2nd, and while it was not as active or extensive as AR2443 it was a substantial group in its own right.

It was on the 4th, as AR2443 reached the Central Meridian (the imaginary centre-line of the solar disk) and AR2445 was near the W limb, that AR2443 (now a type Eac) produced a fairly weak M-class solar flare. This led to some high-latitude aurora around the nights of the 6th and 7th but having done this, AR2443 began to slowly decay as it was carried westwards over the next few days, reaching the W limb on the 10th.

Also on the solar disk at this time was slowly developing sunspot AR2449. This was type Dao on the 9th, and it produced an M-class solar flare the same day adding to the already disturbed solar wind stream buffeting the Earth and producing aurora at high latitudes.

From then on we had a quiet Sun with only the occasional small sunspots to be seen. Developing sunspot AR2454 which was by then nearing the W limb, producing some minor C-class flares from the 19th onwards.
The Earth though was passing through the effects of a Coronal Mass Ejection (CME) that had erupted on the Sun on the 18th, producing some very active aurora as far south as Iceland.

As we headed towards the end of November, AR2457 and AR2458 had appeared over the E limb around the 20th and the 23rd respectively. AR2457 seemed it could be solar flare active but in the end it did not produce anything.

From the 27th onwards we had AR2457 (now a type Hax) and AR2458 (type Cao) now lying either side of the CM the latter had a main spot with penumbra and a wide scattering of smaller spots following. Also visible was AR2459 a pair of sunspots.

If you want to know more about the sunspot classification see:
http://www.popastro.com/solar/solarobserving/chapter.php?id_pag=358  (4th item under 'SOLAR') on the SPA website (items 4 and 5).

SPA Sunspot Mean Daily Frequency (MDF): 2.43
SPA Relative Sunspot Number: 42.12

PROMINENCES, PLAGE, AND FILAMENTS
   
The poor weather and low Sun prevented many from observing. From the observations and images received, I can see that the beginning of November as we saw AR2443 and AR2445 crossing the solar disk, there were bright plages surrounding the sunspot groups clearly visible in the H-alpha and Calcium light (CaK) images kindly provided by Julia Wilkinson and Peter Paice.

Later in the month we had a large ‘U’-shaped filament that was seen from the 12th to the 16th. Richard Bailey did a fantastic job of imaging this filament on the 13th. This was also mentioned on the Spaceweather.com website.  

Towards the end of November plages were seen associated AR2454 and AR2457 with some filaments and prominences situated nearby, and an active arch-type prominence, imaged by Richard Bailey on the 26th and 28th.

SPA Prominence Mean Daily Frequency (MDF): 4.24
 
Well done to Jonathan Shanklin observed the Sun on 17 days and Alan Heath on 15 days.

Detailed count records of Active Regions and Relative Sunspot Numbers came from: Richard Bailey, Michael Fullerton, Alan Heath, Mick Jenkins, Ian Lee, Jonathan Shanklin and Julia Wilkinson.

Images and drawings were supplied by: Richard Bailey, Carl Bowron, Mick Jenkins, Ian Lee, Cliff Meredith, Peter Paice, Julia Wilkinson and Brian Woosnam.

My thanks to Alan Clitherow who emailed me a Solation. This is a recording, made with un-exposed and undeveloped photographic paper sealed in a light-tight box with a pin-hole in it (so making a pin-hole camera). This device is placed securely somewhere outside facing south and the pin-hole uncovered. The idea is to leave it undisturbed for about a year. After this time you carefully cover the pinhole and take the box inside. Open the box in darkness, so as to not ruin the exposure, take out the paper and develop it. The result is a multitude of curved lines traced by the Sun as it crossed the sky from east to west each clear day over the year. You can see Alan’s Solation at http://www.popastro.com/solar/news/newsdetail.php?id_nw=408

A Merry Christmas and a Happy New Year to all.

Geoff Elston

Director

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