W63 is an old, large supernova remnant in the constellation Cygnus. It is roughly 5,000 to 10,000 light-years away. The glowing, expanding blue elliptical-shaped shock shell spans roughly 150 light-years across (about 95 by 65 arcminutes).
It is very very faint. It took several nights of stacking to really begin to see the OIII filaments. This image is a two panel mosaic.