Ordinary Meeting, 2005 October 26


Eclipse Observations

Mr James opened by giving the circumstances of the eclipse, which had been visible in its annular phase along a path which traversed Spain, Portugal and parts of Africa; it had started at 08:55 (09:05) UT in Portugal (and southern Spain), and lasted 4m10 (4m20). A partial eclipse had been visible from London between 07h49 and 10h19 UT, to a maximum of 66.1%.

The speaker, and a number of other Association members, had taken advantage of cheap airfares to fly to Madrid for a long weekend, and had viewed the eclipse from Valencia. Others had observed from Tunisia, while many others still, of course, had watched the partial event visible from the UK. Spain had enjoyed clear skies throughout; the Tunisian groups had had some worries about localised cloud patches, but in the event they had not affected anyone of whom the speaker was aware. Many in the UK had been clouded out, though there had been some clear patches, especially in the south-east.

Martin Mobberley, in Suffolk, had imaged some of the partial phase through a thin veil of cloud; in Worcester Park, Maurice Gavin had had good enough skies to take a series of images, later to be stacked into a fine composite, which revealed clearly the magnitude of the eclipse. In Surrey, John Murrell had taken another fine series of images by mounting his digital SLR onto the back of his telescope.

Mr James then showed some of the images from Valencia – firstly those by Damian Peach and David Tyler, taken during annularity. The resolution achieved was astounding – some aspherical details were even apparent on the lunar limb. The speaker was unsure whether these were lunar mountains, as he might like to believe, or seeing effects; in either case the images remained superb. Pete Laurence had obtained a fine image of the central moment of the annularity, when the Sun had appeared to form a perfect ring. Perhaps the best images of third contact were those by Glyn Marsh, who had captured the annulus breaking up into a whole series of many Bailey's Beads; these were without question the result of lunar topography, the Sun setting first behind the mountains, lingering a little longer above the valleys, each for a moment like a sparkling bead until solar limb crept beneath their floors also.

In Tunisia, Nigel Evans had attempted successfully to take a composite image of the eclipse, using film rather than digital stacking – the old-fashioned way. A fair amount of advanced planning had been required, to frame the shot appropriately and select a suitable exposure; the speaker congratulated him heartily: he had good reason to be pleased with the result.

Mr James concluded by showing a video that he had taken from Valencia of the annular phase; he also remarked upon one of the most interesting demonstrations that could be done during the partial phases of an eclipse: projecting little crescent images of the Sun through little pin-holes and other crevices.

Following the applause for Mr James' display of images, the President then introduced the evening's final speaker, Dr Stewart Moore, Director of the Deep Sky Section, to discuss the objects which would be visible in coming months.




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