The nebula itself is only a portion of much larger spherical
structure of material ejected during ancient supernova explosion. All
exposures were performed through narrow-band filers to enhance only
particular wavelengths, on which the interstellar gaseous clouds
Thomas used his G2-4000 CCD camera for imaging and G1-0301 camera
for guiding of the ASA 10” corrected Newtonian telescope. Total
exposure time is 80 hours (20 hours were needed for each field).