Sunday, 8 October 2017

Ghostly Clouds of Plasma - 8th October

The sun at first sight seemed deathly quiet today when I looked on GONG before going out to observe, but as is usually the case with our star it is just a case of looking in the right place and the right wavelength.  The air was surprisingly clear so I knew despite poor seeing looking in calcium wavelengths was going to be worthwhile.  Only the day before the active regions that had survived 2 rotations, producing the largest flares of this solar cycle rotated out of view over the limb.  However such large sunspots like that don't just effects in the photosphere, they are active in the chromosphere and above.  Today was a great example of this, despite the active regions being over the other side of the limb, the clouds of plasma that sit tens of thousands of kilometres above them were still visible silhouetted against the background of space.  The thin solar chromosphere, some 3000-5000km thick is visible with it's spicules on the limb. This shot was taken with the 40mm scope at 560mm focal length with the PGR Chameleon 3 camera and homebrew CaK filter.