I just went to
http://archive.eso.org/dss/dss
and typed in RA 20 15.35, dec 38 02.8 using a 20'x20' field and DSS2-red.
The dark area is visible in the DSS image and the APOD image has north to the left.
There is a hint of the circle diameter 4' in the DSS1 and DS2-red images.
The main nebula in the lower part of the APOD image (not the circle) is DWB 20. (Dickel, Wendker, Bieritz)