Director: Richard Bailey
AUGUST 2011
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SPA SOLAR SECTION
AUGUST 2011
Rotation Nos. 2113, 2114
WHITE LIGHT
AR activity in the NH was about four times that in the SH and the number of sunspots about seven times, based on statistics from Brian Gordon-States’ detailed records from 28 days of observation. The larger sizes of many NH AR’s also had their affect on sunspot numbers .
Week 1
A line of 3 sizeable NH AR’s, 1260, 61 and 63 plus small 1265 near the W limb showed well, the leading AR just past the CM on the 1st. By the 7th, AR’s1261 and 63 were by the W limb and small SH AR1269 by the CM.
Week 2
A much quieter Sun, only small NH AR1266, 1270 and SH AR1269 were noted.
Week 3
The 15th. had a blank disc, on the 16th. NH AR1271 had appeared at the E limb and was to develop into a good cluster of spots during the week, 12 being seen on the 17th. when small SH AR1272 was seen by the E limb.
Week 4
NH AR1271 continued to grow as it passed the CM, 17 spots being counted including a good leader and follower with penumbra. Small NH AR1274 and SH1272 and 75 showed on the 22nd. 1271 was at the W limb on the 27th and two single spots with penumbra ,close together, AR’s 1277 and 79 had rotated into view in the E. By the end of the month they had moved near the CM. By then other small AR’s had appeared to give 5 across the disc.
Brian . Alan Heath and the Director observed faculae regularly, and Alan’s detailed drawings show the many changes to AR’s 1260,61 and 63 from July 30th. to August 3rd.
MDF 2.48 R 37.52
H-ALPHA
The highlight of the month was the strongest ( X7 rated ) flare of Solar Cycle 24 so far . Alan Heath and the Director were fortunate to be observing at about 0800UT when the large, brilliant flare appeared in NH AR1263, then near the W limb . Alan could see it easily through passing clouds and he judged it was at it’s brightest at 0825UT , and had faded by 0905UT.
Prominences again were regularly seen, many large with complex and everchanging shapes sometimes across days. Lengthy filaments were also often seen , some lasting days, and bright plaging to AR’s. Ian Lee observed some splendid prominencies on the S, N and W limbs on the 15th, a huge W arch dominating, and on the 29th. a large bright hedgerow one on the E limb.
His detailed drawings and descriptions again make a fine record of many observations. Alan Clitherow, Peter Paice and Brian Woosnam again took excellent pictures .
MDF 4.69
Observers : Peter Paice Ian Lee Alan Heath Brian Woosnam
Brian Gordon-States John Docherty Malin Keal and the Director.
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