PST 40 @50X 10:15 U T it seemed to come from a slight depression on the limb.
I never got the chance to observe the big Active Region 1520 but suspected this might be a goodbye wave :-) I like to be accurate in drawing solar features so I can compare my drawings to images taken at more or less the same time. This does two things A) Its feedback on the my accuracy and B) I learn from others who imaged the feature in order to further understand what is going on in my observation. On this occasion my sketch was of a Coronal Loop. Magnetic looped prominences like this often occur after a large explosion on the sun, such was the case in my observation that morning. This powerful activity continued for something like twelve hours.
Image of the loop by Dave Tyler included in the slideshow below.
Once again on July 26th I had the happy chance of observing an enormous twisting prom on the NE limb. Never seen anything like it before, it was a veritable cornucopia of plasma gas swirling from the apparent edge of the sun. The rest of the disc had very busy filaments jumping and twisting like ropes .
I am continually working on techniques to sketch filaments, active regions, flares, and proms. The challenge of capturing the sun on paper is in my opinion one of the most difficult gauntlets to satisfy in astronomical drawing.