This image of the Sun's chromosphere includes a large Sunspot, as well as a thick filament.
Sunspots are caused by twisted magnetic fields that block convection on the Sun's surface.
These images were taken with a Lunt 60mm Hydrogen-Alpha telescope, and a Lumenera Skynyx 2-0 CCD Camera.
The images were processed using Registax and the GIMP. This is a mosaic of two images.