Grand sunspot 2192 imaged in CaK, a spectral band 2.2 angstroms wide, centered at 393.37nm. The view in full visible spectrum light can be seen here.

October 19, 2014/ a single video frame captured with 90mm Coronado CaK telescope used courtesy Dennis Zywiczynski, PGR Grasshopper Express 6 megapixel camera

© Alan Friedman | all rights reserved