Sunspot group in H-alpha light
The observation of the prominent sunspot group in Hydrogen-alpha light (656.3 nanometers)
not only shows the dark sunspots, but also reveals dark filaments and bright active regions.
Note the changes in the spots, filaments and active regions in the course of one day, and
also the different seeing conditions.
Image taken with a Maksutov telephoto lens 1000/10, Coronado 90 H-alpha filter,
Philips Toucam Pro webcam, processed with Giotto software.
Above on 15. May, below on 16. May 2004.