Solar H-Alpha: MAY 3, 2009 – 18:30 UT

H-Alpha Solar Sketch

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Observation Notes:

The solar limb extruded a fantastic prominence today at PA 210 degrees. It took the shape of a calligrapher’s X, or perhaps something like a Cretaceous claw reaching over from the Sun’s far side. I measured it at 1.3/31.2 solar diameters in height, or 58,000 km (36,000 miles). It’s pretty awesome to consider 5 earths could be stacked along its length. Several other gouts of plasma levitated over the solar limb. One in particular at about PA 220 degrees looked like it might form a loop with two bright spots beneath it; however I was only able to spot a brighter segment of the arc. The limb otherwise steadied enough at times to give the impression of sharp, faint, thorny protrusions everywhere. These can’t be spicules, so I need to figure out what they actually are.

Edit – MAY 04, 2005: Alan Friedman posted images he shot of the same prominence at the same time I was making this observation. So I was able to get some photoglaphic feedback on the sketch:

Comparison of photographic and visual sketch of prominence
MAY 3, 2009 – 18:45 UT
Photo posted with permission of Alan Friedman.

I obviously didn’t catch the finer detail, but the broad details seem to match up fairly well. Be sure to have a look at the excellent astrophotography at Alan’s site: Averted Imagination.