This hydrogen-alpha image of part of the Sun was taken on Dec 1, 2011 at 11 am. Several dramatic sunspot groups marked by bright plages are featured: Active Region 1363 at bottom and A.R. 1362 in upper right. A.R. 1364 is less obvious, appearing to the left of A.R. 1362.
A cluster of prominences appears at the bottom, and two dark filaments at upper left. Both prominences and filaments are loops of hot gas following magnetic arcs off the surface of the Sun. Filaments are dark against the bright (higher-density) surface, and prominences are bright against the blackness of space.
This image illustrates that the two observable features represent the same physical phenomenon. One of the filaments, which springs from A.R. 1364, clearly links up to a prominence. Both filament and prominence are part of the same sinuous arc of gas.
The picture was taken with a double-stacked filter, which improves the contrast between the bright plages and dark filaments, and reduces the contrast between the bright surface and fainter prominences.
Telescope: 60mm Hydrogen-alpha telescope with double-stacked filter.
Camera: Lumenera SKYnyx 2-2M