Recently I have provided the international team of professional astronomers led by Dr. David Martinez-Delgado, of Stella Tidal Streams fame, some of my deep NGC 253 data for an impending paper on the faint but huge halo around NGC 253 and I thought some on here may like to see my recent reworks for them, to show this feature
Seen in negative and enhanced luminance it is easier to appreciate the huge size of the very faint extended halo, which in this deep exposure, stretches across 3/4 of a degree of the sky or one and a half times the diameter of the full moon..that's a big galaxy! There is a fair bit of even fainter Milky Way Cirrus dust revealed too.
Its worth noting, this faint feature was revealed with 265min of Luminance data from a reasonably dark sky using a fast 12" Newtonian.
Full image calibration was performed (Darks and Flats) and no targeted local brightening was used in the processing to artificially highlight the halo, all actions were applied globally so the structure and shape is not arbitrary or artificial.
NGC 253 Huge Halo
I can post a link to the paper when it is available
Mike