Cygnus Loop - June, 2021
7nm NB ZWO filters - Televue 127is, ASI6200MM, A-P 1100GTO-AE, SHO Palette
The use of narrowband filters allow the specific wavelengths of light emitted by the gases making up the supernova remnant to reach the camera, while blocking most of the broadband light emitted by the stars. The result is brighter nebulosity and dimmer stars.
Through the use of these filters, the overall structure begins to be revealed.
One can see that hydrogen gas (shown as red nebulosity) has been displaced less that than the green/blue nebulosity offered by oxygen ions. From this, one can infer that the site of the supernova lies somewhere within this image.