It's visible in a lot of Veil Nebula captures but there are almost no captures of it as an isolated object.
It has no designation other than the name Southeast Cloud in Cygnus Loop. There is not much info about it other than that it's used in studies as an isolated area where the shockwave of the supernova is going through.
Below the capture and also an animated GIF, showing the movement of the shockwave from right to left. For that I used captures made in 1953 by the Palomar Schmidt telescope and fitted that over my capture. It is showing some differences since my capture is in Ha/OIII and the Palomar captures are made with Red and Blue filters (I made a 50/50 transparent stack of those 2). But still the movement is very obvious.
And also an oversight from Wikimedia.org where it's indicated.
The full 2880 x 2004px version can be seen here: https://i.ibb.co/42t71nX/Southeastern-knot-cygnus.jpg
Menno


Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC mount (no guiding)
Optolong L-eXtreme filter
Zwo ASI071MC Pro camera
Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
15 x 600sec / Gain 90 / Offset 4
20 x darks, 50 x flats and 50 x darkflats
Stacked with DeepskyStacker
Made a starless version for use in Photoshop with StarNet v2
Siril and Photoshop
Siril: Crop, Histogram, Background Extraction
Photoshop: starless version: Camera Raw Filter darks, lightness, clarity, sharpening), noise reduction NoiseXterminator plug-in.
Stars as overlay, only a bit sharpened.